# Print output for @column tags ?> CaptureRequest - Android SDK | Android Developers

Most visited

Recently visited

CaptureRequest

public final class CaptureRequest
extends CameraMetadata<Key<?>> implements Parcelable

java.lang.Object
   ↳ android.hardware.camera2.CameraMetadata<android.hardware.camera2.CaptureRequest.Key<?>>
     ↳ android.hardware.camera2.CaptureRequest


An immutable package of settings and outputs needed to capture a single image from the camera device.

Contains the configuration for the capture hardware (sensor, lens, flash), the processing pipeline, the control algorithms, and the output buffers. Also contains the list of target Surfaces to send image data to for this capture.

CaptureRequests can be created by using a Builder instance, obtained by calling CameraDevice#createCaptureRequest

CaptureRequests are given to CameraCaptureSession#capture or CameraCaptureSession#setRepeatingRequest to capture images from a camera.

Each request can specify a different subset of target Surfaces for the camera to send the captured data to. All the surfaces used in a request must be part of the surface list given to the last call to CameraDevice#createCaptureSession, when the request is submitted to the session.

For example, a request meant for repeating preview might only include the Surface for the preview SurfaceView or SurfaceTexture, while a high-resolution still capture would also include a Surface from a ImageReader configured for high-resolution JPEG images.

A reprocess capture request allows a previously-captured image from the camera device to be sent back to the device for further processing. It can be created with CameraDevice#createReprocessCaptureRequest, and used with a reprocessable capture session created with CameraDevice#createReprocessableCaptureSession.

See also:

Summary

Nested classes

class CaptureRequest.Builder

A builder for capture requests. 

class CaptureRequest.Key<T>

A Key is used to do capture request field lookups with CaptureResult#get or to set fields with CaptureRequest.Builder#set(Key, Object)

Inherited constants

Fields

public static final Key<Boolean> BLACK_LEVEL_LOCK

Whether black-level compensation is locked to its current values, or is free to vary.

public static final Key<Integer> COLOR_CORRECTION_ABERRATION_MODE

Mode of operation for the chromatic aberration correction algorithm.

public static final Key<RggbChannelVector> COLOR_CORRECTION_GAINS

Gains applying to Bayer raw color channels for white-balance.

public static final Key<Integer> COLOR_CORRECTION_MODE

The mode control selects how the image data is converted from the sensor's native color into linear sRGB color.

public static final Key<ColorSpaceTransform> COLOR_CORRECTION_TRANSFORM

A color transform matrix to use to transform from sensor RGB color space to output linear sRGB color space.

public static final Key<Integer> CONTROL_AE_ANTIBANDING_MODE

The desired setting for the camera device's auto-exposure algorithm's antibanding compensation.

public static final Key<Integer> CONTROL_AE_EXPOSURE_COMPENSATION

Adjustment to auto-exposure (AE) target image brightness.

public static final Key<Boolean> CONTROL_AE_LOCK

Whether auto-exposure (AE) is currently locked to its latest calculated values.

public static final Key<Integer> CONTROL_AE_MODE

The desired mode for the camera device's auto-exposure routine.

public static final Key<Integer> CONTROL_AE_PRECAPTURE_TRIGGER

Whether the camera device will trigger a precapture metering sequence when it processes this request.

public static final Key<MeteringRectangle[]> CONTROL_AE_REGIONS

List of metering areas to use for auto-exposure adjustment.

public static final Key<Range<Integer>> CONTROL_AE_TARGET_FPS_RANGE

Range over which the auto-exposure routine can adjust the capture frame rate to maintain good exposure.

public static final Key<Integer> CONTROL_AF_MODE

Whether auto-focus (AF) is currently enabled, and what mode it is set to.

public static final Key<MeteringRectangle[]> CONTROL_AF_REGIONS

List of metering areas to use for auto-focus.

public static final Key<Integer> CONTROL_AF_TRIGGER

Whether the camera device will trigger autofocus for this request.

public static final Key<Boolean> CONTROL_AWB_LOCK

Whether auto-white balance (AWB) is currently locked to its latest calculated values.

public static final Key<Integer> CONTROL_AWB_MODE

Whether auto-white balance (AWB) is currently setting the color transform fields, and what its illumination target is.

public static final Key<MeteringRectangle[]> CONTROL_AWB_REGIONS

List of metering areas to use for auto-white-balance illuminant estimation.

public static final Key<Integer> CONTROL_CAPTURE_INTENT

Information to the camera device 3A (auto-exposure, auto-focus, auto-white balance) routines about the purpose of this capture, to help the camera device to decide optimal 3A strategy.

public static final Key<Integer> CONTROL_EFFECT_MODE

A special color effect to apply.

public static final Key<Boolean> CONTROL_ENABLE_ZSL

Allow camera device to enable zero-shutter-lag mode for requests with CaptureRequest#CONTROL_CAPTURE_INTENT == STILL_CAPTURE.

public static final Key<Integer> CONTROL_EXTENDED_SCENE_MODE

Whether extended scene mode is enabled for a particular capture request.

public static final Key<Integer> CONTROL_MODE

Overall mode of 3A (auto-exposure, auto-white-balance, auto-focus) control routines.

public static final Key<Integer> CONTROL_POST_RAW_SENSITIVITY_BOOST

The amount of additional sensitivity boost applied to output images after RAW sensor data is captured.

public static final Key<Integer> CONTROL_SCENE_MODE

Control for which scene mode is currently active.

public static final Key<Integer> CONTROL_VIDEO_STABILIZATION_MODE

Whether video stabilization is active.

public static final Key<Float> CONTROL_ZOOM_RATIO

The desired zoom ratio

Instead of using CaptureRequest#SCALER_CROP_REGION with dual purposes of crop and zoom, the application can now choose to use this tag to specify the desired zoom level.

public static final Creator<CaptureRequest> CREATOR

public static final Key<Integer> DISTORTION_CORRECTION_MODE

Mode of operation for the lens distortion correction block.

public static final Key<Integer> EDGE_MODE

Operation mode for edge enhancement.

public static final Key<Integer> FLASH_MODE

The desired mode for for the camera device's flash control.

public static final Key<Integer> HOT_PIXEL_MODE

Operational mode for hot pixel correction.

public static final Key<Location> JPEG_GPS_LOCATION

A location object to use when generating image GPS metadata.

public static final Key<Integer> JPEG_ORIENTATION

The orientation for a JPEG image.

public static final Key<Byte> JPEG_QUALITY

Compression quality of the final JPEG image.

public static final Key<Byte> JPEG_THUMBNAIL_QUALITY

Compression quality of JPEG thumbnail.

public static final Key<Size> JPEG_THUMBNAIL_SIZE

Resolution of embedded JPEG thumbnail.

public static final Key<Float> LENS_APERTURE

The desired lens aperture size, as a ratio of lens focal length to the effective aperture diameter.

public static final Key<Float> LENS_FILTER_DENSITY

The desired setting for the lens neutral density filter(s).

public static final Key<Float> LENS_FOCAL_LENGTH

The desired lens focal length; used for optical zoom.

public static final Key<Float> LENS_FOCUS_DISTANCE

Desired distance to plane of sharpest focus, measured from frontmost surface of the lens.

public static final Key<Integer> LENS_OPTICAL_STABILIZATION_MODE

Sets whether the camera device uses optical image stabilization (OIS) when capturing images.

public static final Key<Integer> NOISE_REDUCTION_MODE

Mode of operation for the noise reduction algorithm.

public static final Key<Float> REPROCESS_EFFECTIVE_EXPOSURE_FACTOR

The amount of exposure time increase factor applied to the original output frame by the application processing before sending for reprocessing.

public static final Key<Rect> SCALER_CROP_REGION

The desired region of the sensor to read out for this capture.

public static final Key<Long> SENSOR_EXPOSURE_TIME

Duration each pixel is exposed to light.

public static final Key<Long> SENSOR_FRAME_DURATION

Duration from start of frame exposure to start of next frame exposure.

public static final Key<Integer> SENSOR_SENSITIVITY

The amount of gain applied to sensor data before processing.

public static final Key<int[]> SENSOR_TEST_PATTERN_DATA

A pixel [R, G_even, G_odd, B] that supplies the test pattern when CaptureRequest#SENSOR_TEST_PATTERN_MODE is SOLID_COLOR.

public static final Key<Integer> SENSOR_TEST_PATTERN_MODE

When enabled, the sensor sends a test pattern instead of doing a real exposure from the camera.

public static final Key<Integer> SHADING_MODE

Quality of lens shading correction applied to the image data.

public static final Key<Integer> STATISTICS_FACE_DETECT_MODE

Operating mode for the face detector unit.

public static final Key<Boolean> STATISTICS_HOT_PIXEL_MAP_MODE

Operating mode for hot pixel map generation.

public static final Key<Integer> STATISTICS_LENS_SHADING_MAP_MODE

Whether the camera device will output the lens shading map in output result metadata.

public static final Key<Integer> STATISTICS_OIS_DATA_MODE

A control for selecting whether optical stabilization (OIS) position information is included in output result metadata.

public static final Key<TonemapCurve> TONEMAP_CURVE

Tonemapping / contrast / gamma curve to use when CaptureRequest#TONEMAP_MODE is CONTRAST_CURVE.

public static final Key<Float> TONEMAP_GAMMA

Tonemapping curve to use when CaptureRequest#TONEMAP_MODE is GAMMA_VALUE

The tonemap curve will be defined the following formula: * OUT = pow(IN, 1.0 / gamma) where IN and OUT is the input pixel value scaled to range [0.0, 1.0], pow is the power function and gamma is the gamma value specified by this key.

public static final Key<Integer> TONEMAP_MODE

High-level global contrast/gamma/tonemapping control.

public static final Key<Integer> TONEMAP_PRESET_CURVE

Tonemapping curve to use when CaptureRequest#TONEMAP_MODE is PRESET_CURVE

The tonemap curve will be defined by specified standard.

Public methods

int describeContents()

Describe the kinds of special objects contained in this Parcelable instance's marshaled representation.

boolean equals(Object other)

Determine whether this CaptureRequest is equal to another CaptureRequest.

<T> T get(Key<T> key)

Get a capture request field value.

List<Key<?>> getKeys()

Returns a list of the keys contained in this map.

Object getTag()

Retrieve the tag for this request, if any.

int hashCode()

Returns a hash code value for the object.

boolean isReprocess()

Determine if this is a reprocess capture request.

void writeToParcel(Parcel dest, int flags)

Flatten this object in to a Parcel.

Inherited methods

Fields

BLACK_LEVEL_LOCK

public static final Key<Boolean> BLACK_LEVEL_LOCK

Whether black-level compensation is locked to its current values, or is free to vary.

When set to true (ON), the values used for black-level compensation will not change until the lock is set to false (OFF).

Since changes to certain capture parameters (such as exposure time) may require resetting of black level compensation, the camera device must report whether setting the black level lock was successful in the output result metadata.

For example, if a sequence of requests is as follows:

  • Request 1: Exposure = 10ms, Black level lock = OFF
  • Request 2: Exposure = 10ms, Black level lock = ON
  • Request 3: Exposure = 10ms, Black level lock = ON
  • Request 4: Exposure = 20ms, Black level lock = ON
  • Request 5: Exposure = 20ms, Black level lock = ON
  • Request 6: Exposure = 20ms, Black level lock = ON

And the exposure change in Request 4 requires the camera device to reset the black level offsets, then the output result metadata is expected to be:

  • Result 1: Exposure = 10ms, Black level lock = OFF
  • Result 2: Exposure = 10ms, Black level lock = ON
  • Result 3: Exposure = 10ms, Black level lock = ON
  • Result 4: Exposure = 20ms, Black level lock = OFF
  • Result 5: Exposure = 20ms, Black level lock = ON
  • Result 6: Exposure = 20ms, Black level lock = ON

This indicates to the application that on frame 4, black levels were reset due to exposure value changes, and pixel values may not be consistent across captures.

The camera device will maintain the lock to the extent possible, only overriding the lock to OFF when changes to other request parameters require a black level recalculation or reset.

Optional - The value for this key may be null on some devices.

Full capability - Present on all camera devices that report being CameraCharacteristics#INFO_SUPPORTED_HARDWARE_LEVEL_FULL devices in the CameraCharacteristics#INFO_SUPPORTED_HARDWARE_LEVEL key

See also:

COLOR_CORRECTION_ABERRATION_MODE

public static final Key<Integer> COLOR_CORRECTION_ABERRATION_MODE

Mode of operation for the chromatic aberration correction algorithm.

Chromatic (color) aberration is caused by the fact that different wavelengths of light can not focus on the same point after exiting from the lens. This metadata defines the high level control of chromatic aberration correction algorithm, which aims to minimize the chromatic artifacts that may occur along the object boundaries in an image.

FAST/HIGH_QUALITY both mean that camera device determined aberration correction will be applied. HIGH_QUALITY mode indicates that the camera device will use the highest-quality aberration correction algorithms, even if it slows down capture rate. FAST means the camera device will not slow down capture rate when applying aberration correction.

LEGACY devices will always be in FAST mode.

Possible values:

Available values for this device:
CameraCharacteristics#COLOR_CORRECTION_AVAILABLE_ABERRATION_MODES

This key is available on all devices.

See also:

COLOR_CORRECTION_GAINS

public static final Key<RggbChannelVector> COLOR_CORRECTION_GAINS

Gains applying to Bayer raw color channels for white-balance.

These per-channel gains are either set by the camera device when the request CaptureRequest#COLOR_CORRECTION_MODE is not TRANSFORM_MATRIX, or directly by the application in the request when the CaptureRequest#COLOR_CORRECTION_MODE is TRANSFORM_MATRIX.

The gains in the result metadata are the gains actually applied by the camera device to the current frame.

The valid range of gains varies on different devices, but gains between [1.0, 3.0] are guaranteed not to be clipped. Even if a given device allows gains below 1.0, this is usually not recommended because this can create color artifacts.

Units: Unitless gain factors

Optional - The value for this key may be null on some devices.

Full capability - Present on all camera devices that report being CameraCharacteristics#INFO_SUPPORTED_HARDWARE_LEVEL_FULL devices in the CameraCharacteristics#INFO_SUPPORTED_HARDWARE_LEVEL key

See also:

COLOR_CORRECTION_MODE

public static final Key<Integer> COLOR_CORRECTION_MODE

The mode control selects how the image data is converted from the sensor's native color into linear sRGB color.

When auto-white balance (AWB) is enabled with CaptureRequest#CONTROL_AWB_MODE, this control is overridden by the AWB routine. When AWB is disabled, the application controls how the color mapping is performed.

We define the expected processing pipeline below. For consistency across devices, this is always the case with TRANSFORM_MATRIX.

When either FAST or HIGH_QUALITY is used, the camera device may do additional processing but CaptureRequest#COLOR_CORRECTION_GAINS and CaptureRequest#COLOR_CORRECTION_TRANSFORM will still be provided by the camera device (in the results) and be roughly correct.

Switching to TRANSFORM_MATRIX and using the data provided from FAST or HIGH_QUALITY will yield a picture with the same white point as what was produced by the camera device in the earlier frame.

The expected processing pipeline is as follows:

White balance processing pipeline

The white balance is encoded by two values, a 4-channel white-balance gain vector (applied in the Bayer domain), and a 3x3 color transform matrix (applied after demosaic).

The 4-channel white-balance gains are defined as:

CaptureRequest#COLOR_CORRECTION_GAINS = [ R G_even G_odd B ]
 

where G_even is the gain for green pixels on even rows of the output, and G_odd is the gain for green pixels on the odd rows. These may be identical for a given camera device implementation; if the camera device does not support a separate gain for even/odd green channels, it will use the G_even value, and write G_odd equal to G_even in the output result metadata.

The matrices for color transforms are defined as a 9-entry vector:

CaptureRequest#COLOR_CORRECTION_TRANSFORM = [ I0 I1 I2 I3 I4 I5 I6 I7 I8 ]
 

which define a transform from input sensor colors, P_in = [ r g b ], to output linear sRGB, P_out = [ r' g' b' ],

with colors as follows:

r' = I0r + I1g + I2b
 g' = I3r + I4g + I5b
 b' = I6r + I7g + I8b
 

Both the input and output value ranges must match. Overflow/underflow values are clipped to fit within the range.

Possible values:

Optional - The value for this key may be null on some devices.

Full capability - Present on all camera devices that report being CameraCharacteristics#INFO_SUPPORTED_HARDWARE_LEVEL_FULL devices in the CameraCharacteristics#INFO_SUPPORTED_HARDWARE_LEVEL key

See also:

COLOR_CORRECTION_TRANSFORM

public static final Key<ColorSpaceTransform> COLOR_CORRECTION_TRANSFORM

A color transform matrix to use to transform from sensor RGB color space to output linear sRGB color space.

This matrix is either set by the camera device when the request CaptureRequest#COLOR_CORRECTION_MODE is not TRANSFORM_MATRIX, or directly by the application in the request when the CaptureRequest#COLOR_CORRECTION_MODE is TRANSFORM_MATRIX.

In the latter case, the camera device may round the matrix to account for precision issues; the final rounded matrix should be reported back in this matrix result metadata. The transform should keep the magnitude of the output color values within [0, 1.0] (assuming input color values is within the normalized range [0, 1.0]), or clipping may occur.

The valid range of each matrix element varies on different devices, but values within [-1.5, 3.0] are guaranteed not to be clipped.

Units: Unitless scale factors

Optional - The value for this key may be null on some devices.

Full capability - Present on all camera devices that report being CameraCharacteristics#INFO_SUPPORTED_HARDWARE_LEVEL_FULL devices in the CameraCharacteristics#INFO_SUPPORTED_HARDWARE_LEVEL key

See also:

CONTROL_AE_ANTIBANDING_MODE

public static final Key<Integer> CONTROL_AE_ANTIBANDING_MODE

The desired setting for the camera device's auto-exposure algorithm's antibanding compensation.

Some kinds of lighting fixtures, such as some fluorescent lights, flicker at the rate of the power supply frequency (60Hz or 50Hz, depending on country). While this is typically not noticeable to a person, it can be visible to a camera device. If a camera sets its exposure time to the wrong value, the flicker may become visible in the viewfinder as flicker or in a final captured image, as a set of variable-brightness bands across the image.

Therefore, the auto-exposure routines of camera devices include antibanding routines that ensure that the chosen exposure value will not cause such banding. The choice of exposure time depends on the rate of flicker, which the camera device can detect automatically, or the expected rate can be selected by the application using this control.

A given camera device may not support all of the possible options for the antibanding mode. The CameraCharacteristics#CONTROL_AE_AVAILABLE_ANTIBANDING_MODES key contains the available modes for a given camera device.

AUTO mode is the default if it is available on given camera device. When AUTO mode is not available, the default will be either 50HZ or 60HZ, and both 50HZ and 60HZ will be available.

If manual exposure control is enabled (by setting CaptureRequest#CONTROL_AE_MODE or CaptureRequest#CONTROL_MODE to OFF), then this setting has no effect, and the application must ensure it selects exposure times that do not cause banding issues. The CaptureResult#STATISTICS_SCENE_FLICKER key can assist the application in this.

Possible values:

Available values for this device:

CameraCharacteristics#CONTROL_AE_AVAILABLE_ANTIBANDING_MODES

This key is available on all devices.

See also:

CONTROL_AE_EXPOSURE_COMPENSATION

public static final Key<Integer> CONTROL_AE_EXPOSURE_COMPENSATION

Adjustment to auto-exposure (AE) target image brightness.

The adjustment is measured as a count of steps, with the step size defined by CameraCharacteristics#CONTROL_AE_COMPENSATION_STEP and the allowed range by CameraCharacteristics#CONTROL_AE_COMPENSATION_RANGE.

For example, if the exposure value (EV) step is 0.333, '6' will mean an exposure compensation of +2 EV; -3 will mean an exposure compensation of -1 EV. One EV represents a doubling of image brightness. Note that this control will only be effective if CaptureRequest#CONTROL_AE_MODE != OFF. This control will take effect even when CaptureRequest#CONTROL_AE_LOCK == true.

In the event of exposure compensation value being changed, camera device may take several frames to reach the newly requested exposure target. During that time, CaptureResult#CONTROL_AE_STATE field will be in the SEARCHING state. Once the new exposure target is reached, CaptureResult#CONTROL_AE_STATE will change from SEARCHING to either CONVERGED, LOCKED (if AE lock is enabled), or FLASH_REQUIRED (if the scene is too dark for still capture).

Units: Compensation steps

Range of valid values:
CameraCharacteristics#CONTROL_AE_COMPENSATION_RANGE

This key is available on all devices.

See also:

CONTROL_AE_LOCK

public static final Key<Boolean> CONTROL_AE_LOCK

Whether auto-exposure (AE) is currently locked to its latest calculated values.

When set to true (ON), the AE algorithm is locked to its latest parameters, and will not change exposure settings until the lock is set to false (OFF).

Note that even when AE is locked, the flash may be fired if the CaptureRequest#CONTROL_AE_MODE is ON_AUTO_FLASH / ON_ALWAYS_FLASH / ON_AUTO_FLASH_REDEYE.

When CaptureRequest#CONTROL_AE_EXPOSURE_COMPENSATION is changed, even if the AE lock is ON, the camera device will still adjust its exposure value.

If AE precapture is triggered (see CaptureRequest#CONTROL_AE_PRECAPTURE_TRIGGER) when AE is already locked, the camera device will not change the exposure time (CaptureRequest#SENSOR_EXPOSURE_TIME) and sensitivity (CaptureRequest#SENSOR_SENSITIVITY) parameters. The flash may be fired if the CaptureRequest#CONTROL_AE_MODE is ON_AUTO_FLASH/ON_AUTO_FLASH_REDEYE and the scene is too dark. If the CaptureRequest#CONTROL_AE_MODE is ON_ALWAYS_FLASH, the scene may become overexposed. Similarly, AE precapture trigger CANCEL has no effect when AE is already locked.

When an AE precapture sequence is triggered, AE unlock will not be able to unlock the AE if AE is locked by the camera device internally during precapture metering sequence In other words, submitting requests with AE unlock has no effect for an ongoing precapture metering sequence. Otherwise, the precapture metering sequence will never succeed in a sequence of preview requests where AE lock is always set to false.

Since the camera device has a pipeline of in-flight requests, the settings that get locked do not necessarily correspond to the settings that were present in the latest capture result received from the camera device, since additional captures and AE updates may have occurred even before the result was sent out. If an application is switching between automatic and manual control and wishes to eliminate any flicker during the switch, the following procedure is recommended:

  1. Starting in auto-AE mode:
  2. Lock AE
  3. Wait for the first result to be output that has the AE locked
  4. Copy exposure settings from that result into a request, set the request to manual AE
  5. Submit the capture request, proceed to run manual AE as desired.

See CaptureResult#CONTROL_AE_STATE for AE lock related state transition details.

This key is available on all devices.

See also:

CONTROL_AE_MODE

public static final Key<Integer> CONTROL_AE_MODE

The desired mode for the camera device's auto-exposure routine.

This control is only effective if CaptureRequest#CONTROL_MODE is AUTO.

When set to any of the ON modes, the camera device's auto-exposure routine is enabled, overriding the application's selected exposure time, sensor sensitivity, and frame duration (CaptureRequest#SENSOR_EXPOSURE_TIME, CaptureRequest#SENSOR_SENSITIVITY, and CaptureRequest#SENSOR_FRAME_DURATION). If one of the FLASH modes is selected, the camera device's flash unit controls are also overridden.

The FLASH modes are only available if the camera device has a flash unit (CameraCharacteristics#FLASH_INFO_AVAILABLE is true).

If flash TORCH mode is desired, this field must be set to ON or OFF, and CaptureRequest#FLASH_MODE set to TORCH.

When set to any of the ON modes, the values chosen by the camera device auto-exposure routine for the overridden fields for a given capture will be available in its CaptureResult.

Possible values:

Available values for this device:
CameraCharacteristics#CONTROL_AE_AVAILABLE_MODES

This key is available on all devices.

See also:

CONTROL_AE_PRECAPTURE_TRIGGER

public static final Key<Integer> CONTROL_AE_PRECAPTURE_TRIGGER

Whether the camera device will trigger a precapture metering sequence when it processes this request.

This entry is normally set to IDLE, or is not included at all in the request settings. When included and set to START, the camera device will trigger the auto-exposure (AE) precapture metering sequence.

When set to CANCEL, the camera device will cancel any active precapture metering trigger, and return to its initial AE state. If a precapture metering sequence is already completed, and the camera device has implicitly locked the AE for subsequent still capture, the CANCEL trigger will unlock the AE and return to its initial AE state.

The precapture sequence should be triggered before starting a high-quality still capture for final metering decisions to be made, and for firing pre-capture flash pulses to estimate scene brightness and required final capture flash power, when the flash is enabled.

Normally, this entry should be set to START for only a single request, and the application should wait until the sequence completes before starting a new one.

When a precapture metering sequence is finished, the camera device may lock the auto-exposure routine internally to be able to accurately expose the subsequent still capture image (CaptureRequest#CONTROL_CAPTURE_INTENT == STILL_CAPTURE). For this case, the AE may not resume normal scan if no subsequent still capture is submitted. To ensure that the AE routine restarts normal scan, the application should submit a request with CaptureRequest#CONTROL_AE_LOCK == true, followed by a request with CaptureRequest#CONTROL_AE_LOCK == false, if the application decides not to submit a still capture request after the precapture sequence completes. Alternatively, for API level 23 or newer devices, the CANCEL can be used to unlock the camera device internally locked AE if the application doesn't submit a still capture request after the AE precapture trigger. Note that, the CANCEL was added in API level 23, and must not be used in devices that have earlier API levels.

The exact effect of auto-exposure (AE) precapture trigger depends on the current AE mode and state; see CaptureResult#CONTROL_AE_STATE for AE precapture state transition details.

On LEGACY-level devices, the precapture trigger is not supported; capturing a high-resolution JPEG image will automatically trigger a precapture sequence before the high-resolution capture, including potentially firing a pre-capture flash.

Using the precapture trigger and the auto-focus trigger CaptureRequest#CONTROL_AF_TRIGGER simultaneously is allowed. However, since these triggers often require cooperation between the auto-focus and auto-exposure routines (for example, the may need to be enabled for a focus sweep), the camera device may delay acting on a later trigger until the previous trigger has been fully handled. This may lead to longer intervals between the trigger and changes to CaptureResult#CONTROL_AE_STATE indicating the start of the precapture sequence, for example.

If both the precapture and the auto-focus trigger are activated on the same request, then the camera device will complete them in the optimal order for that device.

Possible values:

Optional - The value for this key may be null on some devices.

Limited capability - Present on all camera devices that report being at least CameraCharacteristics#INFO_SUPPORTED_HARDWARE_LEVEL_LIMITED devices in the CameraCharacteristics#INFO_SUPPORTED_HARDWARE_LEVEL key

See also:

CONTROL_AE_REGIONS

public static final Key<MeteringRectangle[]> CONTROL_AE_REGIONS

List of metering areas to use for auto-exposure adjustment.

Not available if CameraCharacteristics#CONTROL_MAX_REGIONS_AE is 0. Otherwise will always be present.

The maximum number of regions supported by the device is determined by the value of CameraCharacteristics#CONTROL_MAX_REGIONS_AE.

For devices not supporting CaptureRequest#DISTORTION_CORRECTION_MODE control, the coordinate system always follows that of CameraCharacteristics#SENSOR_INFO_ACTIVE_ARRAY_SIZE, with (0,0) being the top-left pixel in the active pixel array, and (CameraCharacteristics#SENSOR_INFO_ACTIVE_ARRAY_SIZE.width - 1, CameraCharacteristics#SENSOR_INFO_ACTIVE_ARRAY_SIZE.height - 1) being the bottom-right pixel in the active pixel array.

For devices supporting CaptureRequest#DISTORTION_CORRECTION_MODE control, the coordinate system depends on the mode being set. When the distortion correction mode is OFF, the coordinate system follows CameraCharacteristics#SENSOR_INFO_PRE_CORRECTION_ACTIVE_ARRAY_SIZE, with (0, 0) being the top-left pixel of the pre-correction active array, and (CameraCharacteristics#SENSOR_INFO_PRE_CORRECTION_ACTIVE_ARRAY_SIZE.width - 1, CameraCharacteristics#SENSOR_INFO_PRE_CORRECTION_ACTIVE_ARRAY_SIZE.height - 1) being the bottom-right pixel in the pre-correction active pixel array. When the distortion correction mode is not OFF, the coordinate system follows CameraCharacteristics#SENSOR_INFO_ACTIVE_ARRAY_SIZE, with (0, 0) being the top-left pixel of the active array, and (CameraCharacteristics#SENSOR_INFO_ACTIVE_ARRAY_SIZE.width - 1, CameraCharacteristics#SENSOR_INFO_ACTIVE_ARRAY_SIZE.height - 1) being the bottom-right pixel in the active pixel array.

The weight must be within [0, 1000], and represents a weight for every pixel in the area. This means that a large metering area with the same weight as a smaller area will have more effect in the metering result. Metering areas can partially overlap and the camera device will add the weights in the overlap region.

The weights are relative to weights of other exposure metering regions, so if only one region is used, all non-zero weights will have the same effect. A region with 0 weight is ignored.

If all regions have 0 weight, then no specific metering area needs to be used by the camera device.

If the metering region is outside the used CaptureRequest#SCALER_CROP_REGION returned in capture result metadata, the camera device will ignore the sections outside the crop region and output only the intersection rectangle as the metering region in the result metadata. If the region is entirely outside the crop region, it will be ignored and not reported in the result metadata.

Starting from API level 30, the coordinate system of activeArraySize or preCorrectionActiveArraySize is used to represent post-zoomRatio field of view, not pre-zoom field of view. This means that the same aeRegions values at different CaptureRequest#CONTROL_ZOOM_RATIO represent different parts of the scene. The aeRegions coordinates are relative to the activeArray/preCorrectionActiveArray representing the zoomed field of view. If CaptureRequest#CONTROL_ZOOM_RATIO is set to 1.0 (default), the same aeRegions at different CaptureRequest#SCALER_CROP_REGION still represent the same parts of the scene as they do before. See CaptureRequest#CONTROL_ZOOM_RATIO for details. Whether to use activeArraySize or preCorrectionActiveArraySize still depends on distortion correction mode.

Units: Pixel coordinates within CameraCharacteristics#SENSOR_INFO_ACTIVE_ARRAY_SIZE or CameraCharacteristics#SENSOR_INFO_PRE_CORRECTION_ACTIVE_ARRAY_SIZE depending on distortion correction capability and mode

Range of valid values:
Coordinates must be between [(0,0), (width, height)) of CameraCharacteristics#SENSOR_INFO_ACTIVE_ARRAY_SIZE or CameraCharacteristics#SENSOR_INFO_PRE_CORRECTION_ACTIVE_ARRAY_SIZE depending on distortion correction capability and mode

Optional - The value for this key may be null on some devices.

See also:

CONTROL_AE_TARGET_FPS_RANGE

public static final Key<Range<Integer>> CONTROL_AE_TARGET_FPS_RANGE

Range over which the auto-exposure routine can adjust the capture frame rate to maintain good exposure.

Only constrains auto-exposure (AE) algorithm, not manual control of CaptureRequest#SENSOR_EXPOSURE_TIME and CaptureRequest#SENSOR_FRAME_DURATION.

Units: Frames per second (FPS)

Range of valid values:
Any of the entries in CameraCharacteristics#CONTROL_AE_AVAILABLE_TARGET_FPS_RANGES

This key is available on all devices.

See also:

CONTROL_AF_MODE

public static final Key<Integer> CONTROL_AF_MODE

Whether auto-focus (AF) is currently enabled, and what mode it is set to.

Only effective if CaptureRequest#CONTROL_MODE = AUTO and the lens is not fixed focus (i.e. CameraCharacteristics#LENS_INFO_MINIMUM_FOCUS_DISTANCE > 0). Also note that when CaptureRequest#CONTROL_AE_MODE is OFF, the behavior of AF is device dependent. It is recommended to lock AF by using CaptureRequest#CONTROL_AF_TRIGGER before setting CaptureRequest#CONTROL_AE_MODE to OFF, or set AF mode to OFF when AE is OFF.

If the lens is controlled by the camera device auto-focus algorithm, the camera device will report the current AF status in CaptureResult#CONTROL_AF_STATE in result metadata.

Possible values:

Available values for this device:
CameraCharacteristics#CONTROL_AF_AVAILABLE_MODES

This key is available on all devices.

See also:

CONTROL_AF_REGIONS

public static final Key<MeteringRectangle[]> CONTROL_AF_REGIONS

List of metering areas to use for auto-focus.

Not available if CameraCharacteristics#CONTROL_MAX_REGIONS_AF is 0. Otherwise will always be present.

The maximum number of focus areas supported by the device is determined by the value of CameraCharacteristics#CONTROL_MAX_REGIONS_AF.

For devices not supporting CaptureRequest#DISTORTION_CORRECTION_MODE control, the coordinate system always follows that of CameraCharacteristics#SENSOR_INFO_ACTIVE_ARRAY_SIZE, with (0,0) being the top-left pixel in the active pixel array, and (CameraCharacteristics#SENSOR_INFO_ACTIVE_ARRAY_SIZE.width - 1, CameraCharacteristics#SENSOR_INFO_ACTIVE_ARRAY_SIZE.height - 1) being the bottom-right pixel in the active pixel array.

For devices supporting CaptureRequest#DISTORTION_CORRECTION_MODE control, the coordinate system depends on the mode being set. When the distortion correction mode is OFF, the coordinate system follows CameraCharacteristics#SENSOR_INFO_PRE_CORRECTION_ACTIVE_ARRAY_SIZE, with (0, 0) being the top-left pixel of the pre-correction active array, and (CameraCharacteristics#SENSOR_INFO_PRE_CORRECTION_ACTIVE_ARRAY_SIZE.width - 1, CameraCharacteristics#SENSOR_INFO_PRE_CORRECTION_ACTIVE_ARRAY_SIZE.height - 1) being the bottom-right pixel in the pre-correction active pixel array. When the distortion correction mode is not OFF, the coordinate system follows CameraCharacteristics#SENSOR_INFO_ACTIVE_ARRAY_SIZE, with (0, 0) being the top-left pixel of the active array, and (CameraCharacteristics#SENSOR_INFO_ACTIVE_ARRAY_SIZE.width - 1, CameraCharacteristics#SENSOR_INFO_ACTIVE_ARRAY_SIZE.height - 1) being the bottom-right pixel in the active pixel array.

The weight must be within [0, 1000], and represents a weight for every pixel in the area. This means that a large metering area with the same weight as a smaller area will have more effect in the metering result. Metering areas can partially overlap and the camera device will add the weights in the overlap region.

The weights are relative to weights of other metering regions, so if only one region is used, all non-zero weights will have the same effect. A region with 0 weight is ignored.

If all regions have 0 weight, then no specific metering area needs to be used by the camera device. The capture result will either be a zero weight region as well, or the region selected by the camera device as the focus area of interest.

If the metering region is outside the used CaptureRequest#SCALER_CROP_REGION returned in capture result metadata, the camera device will ignore the sections outside the crop region and output only the intersection rectangle as the metering region in the result metadata. If the region is entirely outside the crop region, it will be ignored and not reported in the result metadata.

Starting from API level 30, the coordinate system of activeArraySize or preCorrectionActiveArraySize is used to represent post-zoomRatio field of view, not pre-zoom field of view. This means that the same afRegions values at different CaptureRequest#CONTROL_ZOOM_RATIO represent different parts of the scene. The afRegions coordinates are relative to the activeArray/preCorrectionActiveArray representing the zoomed field of view. If CaptureRequest#CONTROL_ZOOM_RATIO is set to 1.0 (default), the same afRegions at different CaptureRequest#SCALER_CROP_REGION still represent the same parts of the scene as they do before. See CaptureRequest#CONTROL_ZOOM_RATIO for details. Whether to use activeArraySize or preCorrectionActiveArraySize still depends on distortion correction mode.

Units: Pixel coordinates within CameraCharacteristics#SENSOR_INFO_ACTIVE_ARRAY_SIZE or CameraCharacteristics#SENSOR_INFO_PRE_CORRECTION_ACTIVE_ARRAY_SIZE depending on distortion correction capability and mode

Range of valid values:
Coordinates must be between [(0,0), (width, height)) of CameraCharacteristics#SENSOR_INFO_ACTIVE_ARRAY_SIZE or CameraCharacteristics#SENSOR_INFO_PRE_CORRECTION_ACTIVE_ARRAY_SIZE depending on distortion correction capability and mode

Optional - The value for this key may be null on some devices.

See also:

CONTROL_AF_TRIGGER

public static final Key<Integer> CONTROL_AF_TRIGGER

Whether the camera device will trigger autofocus for this request.

This entry is normally set to IDLE, or is not included at all in the request settings.

When included and set to START, the camera device will trigger the autofocus algorithm. If autofocus is disabled, this trigger has no effect.

When set to CANCEL, the camera device will cancel any active trigger, and return to its initial AF state.

Generally, applications should set this entry to START or CANCEL for only a single capture, and then return it to IDLE (or not set at all). Specifying START for multiple captures in a row means restarting the AF operation over and over again.

See CaptureResult#CONTROL_AF_STATE for what the trigger means for each AF mode.

Using the autofocus trigger and the precapture trigger CaptureRequest#CONTROL_AE_PRECAPTURE_TRIGGER simultaneously is allowed. However, since these triggers often require cooperation between the auto-focus and auto-exposure routines (for example, the may need to be enabled for a focus sweep), the camera device may delay acting on a later trigger until the previous trigger has been fully handled. This may lead to longer intervals between the trigger and changes to CaptureResult#CONTROL_AF_STATE, for example.

Possible values:

This key is available on all devices.

See also:

CONTROL_AWB_LOCK

public static final Key<Boolean> CONTROL_AWB_LOCK

Whether auto-white balance (AWB) is currently locked to its latest calculated values.

When set to true (ON), the AWB algorithm is locked to its latest parameters, and will not change color balance settings until the lock is set to false (OFF).

Since the camera device has a pipeline of in-flight requests, the settings that get locked do not necessarily correspond to the settings that were present in the latest capture result received from the camera device, since additional captures and AWB updates may have occurred even before the result was sent out. If an application is switching between automatic and manual control and wishes to eliminate any flicker during the switch, the following procedure is recommended:

  1. Starting in auto-AWB mode:
  2. Lock AWB
  3. Wait for the first result to be output that has the AWB locked
  4. Copy AWB settings from that result into a request, set the request to manual AWB
  5. Submit the capture request, proceed to run manual AWB as desired.

Note that AWB lock is only meaningful when CaptureRequest#CONTROL_AWB_MODE is in the AUTO mode; in other modes, AWB is already fixed to a specific setting.

Some LEGACY devices may not support ON; the value is then overridden to OFF.

This key is available on all devices.

See also:

CONTROL_AWB_MODE

public static final Key<Integer> CONTROL_AWB_MODE

Whether auto-white balance (AWB) is currently setting the color transform fields, and what its illumination target is.

This control is only effective if CaptureRequest#CONTROL_MODE is AUTO.

When set to the ON mode, the camera device's auto-white balance routine is enabled, overriding the application's selected CaptureRequest#COLOR_CORRECTION_TRANSFORM, CaptureRequest#COLOR_CORRECTION_GAINS and CaptureRequest#COLOR_CORRECTION_MODE. Note that when CaptureRequest#CONTROL_AE_MODE is OFF, the behavior of AWB is device dependent. It is recommened to also set AWB mode to OFF or lock AWB by using CaptureRequest#CONTROL_AWB_LOCK before setting AE mode to OFF.

When set to the OFF mode, the camera device's auto-white balance routine is disabled. The application manually controls the white balance by CaptureRequest#COLOR_CORRECTION_TRANSFORM, CaptureRequest#COLOR_CORRECTION_GAINS and CaptureRequest#COLOR_CORRECTION_MODE.

When set to any other modes, the camera device's auto-white balance routine is disabled. The camera device uses each particular illumination target for white balance adjustment. The application's values for CaptureRequest#COLOR_CORRECTION_TRANSFORM, CaptureRequest#COLOR_CORRECTION_GAINS and CaptureRequest#COLOR_CORRECTION_MODE are ignored.

Possible values:

Available values for this device:
CameraCharacteristics#CONTROL_AWB_AVAILABLE_MODES

This key is available on all devices.

See also:

CONTROL_AWB_REGIONS

public static final Key<MeteringRectangle[]> CONTROL_AWB_REGIONS

List of metering areas to use for auto-white-balance illuminant estimation.

Not available if CameraCharacteristics#CONTROL_MAX_REGIONS_AWB is 0. Otherwise will always be present.

The maximum number of regions supported by the device is determined by the value of CameraCharacteristics#CONTROL_MAX_REGIONS_AWB.

For devices not supporting CaptureRequest#DISTORTION_CORRECTION_MODE control, the coordinate system always follows that of CameraCharacteristics#SENSOR_INFO_ACTIVE_ARRAY_SIZE, with (0,0) being the top-left pixel in the active pixel array, and (CameraCharacteristics#SENSOR_INFO_ACTIVE_ARRAY_SIZE.width - 1, CameraCharacteristics#SENSOR_INFO_ACTIVE_ARRAY_SIZE.height - 1) being the bottom-right pixel in the active pixel array.

For devices supporting CaptureRequest#DISTORTION_CORRECTION_MODE control, the coordinate system depends on the mode being set. When the distortion correction mode is OFF, the coordinate system follows CameraCharacteristics#SENSOR_INFO_PRE_CORRECTION_ACTIVE_ARRAY_SIZE, with (0, 0) being the top-left pixel of the pre-correction active array, and (CameraCharacteristics#SENSOR_INFO_PRE_CORRECTION_ACTIVE_ARRAY_SIZE.width - 1, CameraCharacteristics#SENSOR_INFO_PRE_CORRECTION_ACTIVE_ARRAY_SIZE.height - 1) being the bottom-right pixel in the pre-correction active pixel array. When the distortion correction mode is not OFF, the coordinate system follows CameraCharacteristics#SENSOR_INFO_ACTIVE_ARRAY_SIZE, with (0, 0) being the top-left pixel of the active array, and (CameraCharacteristics#SENSOR_INFO_ACTIVE_ARRAY_SIZE.width - 1, CameraCharacteristics#SENSOR_INFO_ACTIVE_ARRAY_SIZE.height - 1) being the bottom-right pixel in the active pixel array.

The weight must range from 0 to 1000, and represents a weight for every pixel in the area. This means that a large metering area with the same weight as a smaller area will have more effect in the metering result. Metering areas can partially overlap and the camera device will add the weights in the overlap region.

The weights are relative to weights of other white balance metering regions, so if only one region is used, all non-zero weights will have the same effect. A region with 0 weight is ignored.

If all regions have 0 weight, then no specific metering area needs to be used by the camera device.

If the metering region is outside the used CaptureRequest#SCALER_CROP_REGION returned in capture result metadata, the camera device will ignore the sections outside the crop region and output only the intersection rectangle as the metering region in the result metadata. If the region is entirely outside the crop region, it will be ignored and not reported in the result metadata.

Starting from API level 30, the coordinate system of activeArraySize or preCorrectionActiveArraySize is used to represent post-zoomRatio field of view, not pre-zoom field of view. This means that the same awbRegions values at different CaptureRequest#CONTROL_ZOOM_RATIO represent different parts of the scene. The awbRegions coordinates are relative to the activeArray/preCorrectionActiveArray representing the zoomed field of view. If CaptureRequest#CONTROL_ZOOM_RATIO is set to 1.0 (default), the same awbRegions at different CaptureRequest#SCALER_CROP_REGION still represent the same parts of the scene as they do before. See CaptureRequest#CONTROL_ZOOM_RATIO for details. Whether to use activeArraySize or preCorrectionActiveArraySize still depends on distortion correction mode.

Units: Pixel coordinates within CameraCharacteristics#SENSOR_INFO_ACTIVE_ARRAY_SIZE or CameraCharacteristics#SENSOR_INFO_PRE_CORRECTION_ACTIVE_ARRAY_SIZE depending on distortion correction capability and mode

Range of valid values:
Coordinates must be between [(0,0), (width, height)) of CameraCharacteristics#SENSOR_INFO_ACTIVE_ARRAY_SIZE or CameraCharacteristics#SENSOR_INFO_PRE_CORRECTION_ACTIVE_ARRAY_SIZE depending on distortion correction capability and mode

Optional - The value for this key may be null on some devices.

See also:

CONTROL_CAPTURE_INTENT

public static final Key<Integer> CONTROL_CAPTURE_INTENT

Information to the camera device 3A (auto-exposure, auto-focus, auto-white balance) routines about the purpose of this capture, to help the camera device to decide optimal 3A strategy.

This control (except for MANUAL) is only effective if CaptureRequest#CONTROL_MODE != OFF and any 3A routine is active.

All intents are supported by all devices, except that: * ZERO_SHUTTER_LAG will be supported if CameraCharacteristics#REQUEST_AVAILABLE_CAPABILITIES contains PRIVATE_REPROCESSING or YUV_REPROCESSING. * MANUAL will be supported if CameraCharacteristics#REQUEST_AVAILABLE_CAPABILITIES contains MANUAL_SENSOR. * MOTION_TRACKING will be supported if CameraCharacteristics#REQUEST_AVAILABLE_CAPABILITIES contains MOTION_TRACKING.

Possible values:

This key is available on all devices.

See also:

CONTROL_EFFECT_MODE

public static final Key<Integer> CONTROL_EFFECT_MODE

A special color effect to apply.

When this mode is set, a color effect will be applied to images produced by the camera device. The interpretation and implementation of these color effects is left to the implementor of the camera device, and should not be depended on to be consistent (or present) across all devices.

Possible values:

Available values for this device:
CameraCharacteristics#CONTROL_AVAILABLE_EFFECTS

This key is available on all devices.

See also:

CONTROL_ENABLE_ZSL

public static final Key<Boolean> CONTROL_ENABLE_ZSL

Allow camera device to enable zero-shutter-lag mode for requests with CaptureRequest#CONTROL_CAPTURE_INTENT == STILL_CAPTURE.

If enableZsl is true, the camera device may enable zero-shutter-lag mode for requests with STILL_CAPTURE capture intent. The camera device may use images captured in the past to produce output images for a zero-shutter-lag request. The result metadata including the CaptureResult#SENSOR_TIMESTAMP reflects the source frames used to produce output images. Therefore, the contents of the output images and the result metadata may be out of order compared to previous regular requests. enableZsl does not affect requests with other capture intents.

For example, when requests are submitted in the following order: Request A: enableZsl is ON, CaptureRequest#CONTROL_CAPTURE_INTENT is PREVIEW Request B: enableZsl is ON, CaptureRequest#CONTROL_CAPTURE_INTENT is STILL_CAPTURE

The output images for request B may have contents captured before the output images for request A, and the result metadata for request B may be older than the result metadata for request A.

Note that when enableZsl is true, it is not guaranteed to get output images captured in the past for requests with STILL_CAPTURE capture intent.

For applications targeting SDK versions O and newer, the value of enableZsl in TEMPLATE_STILL_CAPTURE template may be true. The value in other templates is always false if present.

For applications targeting SDK versions older than O, the value of enableZsl in all capture templates is always false if present.

For application-operated ZSL, use CAMERA3_TEMPLATE_ZERO_SHUTTER_LAG template.

Optional - The value for this key may be null on some devices.

See also:

CONTROL_EXTENDED_SCENE_MODE

public static final Key<Integer> CONTROL_EXTENDED_SCENE_MODE

Whether extended scene mode is enabled for a particular capture request.

With bokeh mode, the camera device may blur out the parts of scene that are not in focus, creating a bokeh (or shallow depth of field) effect for people or objects.

When set to BOKEH_STILL_CAPTURE mode with STILL_CAPTURE capture intent, due to the extra processing needed for high quality bokeh effect, the stall may be longer than when capture intent is not STILL_CAPTURE.

When set to BOKEH_STILL_CAPTURE mode with PREVIEW capture intent,

When set to BOKEH_CONTINUOUS mode, configured streams dimension should not exceed this mode's maximum streaming dimension in order to have bokeh effect applied. Bokeh effect may not be available for streams larger than the maximum streaming dimension.

Switching between different extended scene modes may involve reconfiguration of the camera pipeline, resulting in long latency. The application should check this key against the available session keys queried via CameraCharacteristics.getAvailableSessionKeys().

For a logical multi-camera, bokeh may be implemented by stereo vision from sub-cameras with different field of view. As a result, when bokeh mode is enabled, the camera device may override CaptureRequest#SCALER_CROP_REGION or CaptureRequest#CONTROL_ZOOM_RATIO, and the field of view may be smaller than when bokeh mode is off.

Possible values:

Optional - The value for this key may be null on some devices.

See also:

CONTROL_MODE

public static final Key<Integer> CONTROL_MODE

Overall mode of 3A (auto-exposure, auto-white-balance, auto-focus) control routines.

This is a top-level 3A control switch. When set to OFF, all 3A control by the camera device is disabled. The application must set the fields for capture parameters itself.

When set to AUTO, the individual algorithm controls in android.control.* are in effect, such as CaptureRequest#CONTROL_AF_MODE.

When set to USE_SCENE_MODE or USE_EXTENDED_SCENE_MODE, the individual controls in android.control.* are mostly disabled, and the camera device implements one of the scene mode or extended scene mode settings (such as ACTION, SUNSET, PARTY, or BOKEH) as it wishes. The camera device scene mode 3A settings are provided by capture results.

When set to OFF_KEEP_STATE, it is similar to OFF mode, the only difference is that this frame will not be used by camera device background 3A statistics update, as if this frame is never captured. This mode can be used in the scenario where the application doesn't want a 3A manual control capture to affect the subsequent auto 3A capture results.

Possible values:

Available values for this device:
CameraCharacteristics#CONTROL_AVAILABLE_MODES

This key is available on all devices.

See also:

CONTROL_POST_RAW_SENSITIVITY_BOOST

public static final Key<Integer> CONTROL_POST_RAW_SENSITIVITY_BOOST

The amount of additional sensitivity boost applied to output images after RAW sensor data is captured.

Some camera devices support additional digital sensitivity boosting in the camera processing pipeline after sensor RAW image is captured. Such a boost will be applied to YUV/JPEG format output images but will not have effect on RAW output formats like RAW_SENSOR, RAW10, RAW12 or RAW_OPAQUE.

This key will be null for devices that do not support any RAW format outputs. For devices that do support RAW format outputs, this key will always present, and if a device does not support post RAW sensitivity boost, it will list 100 in this key.

If the camera device cannot apply the exact boost requested, it will reduce the boost to the nearest supported value. The final boost value used will be available in the output capture result.

For devices that support post RAW sensitivity boost, the YUV/JPEG output images of such device will have the total sensitivity of CaptureRequest#SENSOR_SENSITIVITY * CaptureRequest#CONTROL_POST_RAW_SENSITIVITY_BOOST / 100 The sensitivity of RAW format images will always be CaptureRequest#SENSOR_SENSITIVITY

This control is only effective if CaptureRequest#CONTROL_AE_MODE or CaptureRequest#CONTROL_MODE is set to OFF; otherwise the auto-exposure algorithm will override this value.

Units: ISO arithmetic units, the same as CaptureRequest#SENSOR_SENSITIVITY

Range of valid values:
CameraCharacteristics#CONTROL_POST_RAW_SENSITIVITY_BOOST_RANGE

Optional - The value for this key may be null on some devices.

See also:

CONTROL_SCENE_MODE

public static final Key<Integer> CONTROL_SCENE_MODE

Control for which scene mode is currently active.

Scene modes are custom camera modes optimized for a certain set of conditions and capture settings.

This is the mode that that is active when CaptureRequest#CONTROL_MODE == USE_SCENE_MODE. Aside from FACE_PRIORITY, these modes will disable CaptureRequest#CONTROL_AE_MODE, CaptureRequest#CONTROL_AWB_MODE, and CaptureRequest#CONTROL_AF_MODE while in use.

The interpretation and implementation of these scene modes is left to the implementor of the camera device. Their behavior will not be consistent across all devices, and any given device may only implement a subset of these modes.

Possible values:

Available values for this device:
CameraCharacteristics#CONTROL_AVAILABLE_SCENE_MODES

This key is available on all devices.

See also:

CONTROL_VIDEO_STABILIZATION_MODE

public static final Key<Integer> CONTROL_VIDEO_STABILIZATION_MODE

Whether video stabilization is active.

Video stabilization automatically warps images from the camera in order to stabilize motion between consecutive frames.

If enabled, video stabilization can modify the CaptureRequest#SCALER_CROP_REGION to keep the video stream stabilized.

Switching between different video stabilization modes may take several frames to initialize, the camera device will report the current mode in capture result metadata. For example, When "ON" mode is requested, the video stabilization modes in the first several capture results may still be "OFF", and it will become "ON" when the initialization is done.

In addition, not all recording sizes or frame rates may be supported for stabilization by a device that reports stabilization support. It is guaranteed that an output targeting a MediaRecorder or MediaCodec will be stabilized if the recording resolution is less than or equal to 1920 x 1080 (width less than or equal to 1920, height less than or equal to 1080), and the recording frame rate is less than or equal to 30fps. At other sizes, the CaptureResult CaptureRequest#CONTROL_VIDEO_STABILIZATION_MODE field will return OFF if the recording output is not stabilized, or if there are no output Surface types that can be stabilized.

If a camera device supports both this mode and OIS (CaptureRequest#LENS_OPTICAL_STABILIZATION_MODE), turning both modes on may produce undesirable interaction, so it is recommended not to enable both at the same time.

Possible values:

This key is available on all devices.

See also:

CONTROL_ZOOM_RATIO

public static final Key<Float> CONTROL_ZOOM_RATIO

The desired zoom ratio

Instead of using CaptureRequest#SCALER_CROP_REGION with dual purposes of crop and zoom, the application can now choose to use this tag to specify the desired zoom level. The CaptureRequest#SCALER_CROP_REGION can still be used to specify the horizontal or vertical crop to achieve aspect ratios different than the native camera sensor.

By using this control, the application gains a simpler way to control zoom, which can be a combination of optical and digital zoom. For example, a multi-camera system may contain more than one lens with different focal lengths, and the user can use optical zoom by switching between lenses. Using zoomRatio has benefits in the scenarios below:

To illustrate, here are several scenarios of different zoom ratios, crop regions, and output streams, for a hypothetical camera device with an active array of size (2000,1500).

  • Camera Configuration:
    • Active array size: 2000x1500 (3 MP, 4:3 aspect ratio)
    • Output stream #1: 640x480 (VGA, 4:3 aspect ratio)
    • Output stream #2: 1280x720 (720p, 16:9 aspect ratio)
  • Case #1: 4:3 crop region with 2.0x zoom ratio
    • Zoomed field of view: 1/4 of original field of view
    • Crop region: Rect(0, 0, 2000, 1500) // (left, top, right, bottom) (post zoom)
  • 4:3 aspect ratio crop diagram
    • 640x480 stream source area: (0, 0, 2000, 1500) (equal to crop region)
    • 1280x720 stream source area: (0, 187, 2000, 1312) (letterboxed)
  • Case #2: 16:9 crop region with 2.0x zoom.
    • Zoomed field of view: 1/4 of original field of view
    • Crop region: Rect(0, 187, 2000, 1312)
    • 16:9 aspect ratio crop diagram
    • 640x480 stream source area: (250, 187, 1750, 1312) (pillarboxed)
    • 1280x720 stream source area: (0, 187, 2000, 1312) (equal to crop region)
  • Case #3: 1:1 crop region with 0.5x zoom out to ultrawide lens.
    • Zoomed field of view: 4x of original field of view (switched from wide lens to ultrawide lens)
    • Crop region: Rect(250, 0, 1750, 1500)
    • 1:1 aspect ratio crop diagram
    • 640x480 stream source area: (250, 187, 1750, 1312) (letterboxed)
    • 1280x720 stream source area: (250, 328, 1750, 1172) (letterboxed)

As seen from the graphs above, the coordinate system of cropRegion now changes to the effective after-zoom field-of-view, and is represented by the rectangle of (0, 0, activeArrayWith, activeArrayHeight). The same applies to AE/AWB/AF regions, and faces. This coordinate system change isn't applicable to RAW capture and its related metadata such as intrinsicCalibration and lensShadingMap.

Using the same hypothetical example above, and assuming output stream #1 (640x480) is the viewfinder stream, the application can achieve 2.0x zoom in one of two ways:

  • zoomRatio = 2.0, scaler.cropRegion = (0, 0, 2000, 1500)
  • zoomRatio = 1.0 (default), scaler.cropRegion = (500, 375, 1500, 1125)

If the application intends to set aeRegions to be top-left quarter of the viewfinder field-of-view, the CaptureRequest#CONTROL_AE_REGIONS should be set to (0, 0, 1000, 750) with zoomRatio set to 2.0. Alternatively, the application can set aeRegions to the equivalent region of (500, 375, 1000, 750) for zoomRatio of 1.0. If the application doesn't explicitly set CaptureRequest#CONTROL_ZOOM_RATIO, its value defaults to 1.0.

One limitation of controlling zoom using zoomRatio is that the CaptureRequest#SCALER_CROP_REGION must only be used for letterboxing or pillarboxing of the sensor active array, and no FREEFORM cropping can be used with CaptureRequest#CONTROL_ZOOM_RATIO other than 1.0.

Range of valid values:
CameraCharacteristics#CONTROL_ZOOM_RATIO_RANGE

Optional - The value for this key may be null on some devices.

Limited capability - Present on all camera devices that report being at least CameraCharacteristics#INFO_SUPPORTED_HARDWARE_LEVEL_LIMITED devices in the CameraCharacteristics#INFO_SUPPORTED_HARDWARE_LEVEL key

See also:

CREATOR

public static final Creator<CaptureRequest> CREATOR

DISTORTION_CORRECTION_MODE

public static final Key<Integer> DISTORTION_CORRECTION_MODE

Mode of operation for the lens distortion correction block.

The lens distortion correction block attempts to improve image quality by fixing radial, tangential, or other geometric aberrations in the camera device's optics. If available, the CameraCharacteristics#LENS_DISTORTION field documents the lens's distortion parameters.

OFF means no distortion correction is done.

FAST/HIGH_QUALITY both mean camera device determined distortion correction will be applied. HIGH_QUALITY mode indicates that the camera device will use the highest-quality correction algorithms, even if it slows down capture rate. FAST means the camera device will not slow down capture rate when applying correction. FAST may be the same as OFF if any correction at all would slow down capture rate. Every output stream will have a similar amount of enhancement applied.

The correction only applies to processed outputs such as YUV, Y8, JPEG, or DEPTH16; it is not applied to any RAW output.

This control will be on by default on devices that support this control. Applications disabling distortion correction need to pay extra attention with the coordinate system of metering regions, crop region, and face rectangles. When distortion correction is OFF, metadata coordinates follow the coordinate system of CameraCharacteristics#SENSOR_INFO_PRE_CORRECTION_ACTIVE_ARRAY_SIZE. When distortion is not OFF, metadata coordinates follow the coordinate system of CameraCharacteristics#SENSOR_INFO_ACTIVE_ARRAY_SIZE. The camera device will map these metadata fields to match the corrected image produced by the camera device, for both capture requests and results. However, this mapping is not very precise, since rectangles do not generally map to rectangles when corrected. Only linear scaling between the active array and precorrection active array coordinates is performed. Applications that require precise correction of metadata need to undo that linear scaling, and apply a more complete correction that takes into the account the app's own requirements.

The full list of metadata that is affected in this way by distortion correction is:

Possible values:

Available values for this device:
CameraCharacteristics#DISTORTION_CORRECTION_AVAILABLE_MODES

Optional - The value for this key may be null on some devices.

See also:

EDGE_MODE

public static final Key<Integer> EDGE_MODE

Operation mode for edge enhancement.

Edge enhancement improves sharpness and details in the captured image. OFF means no enhancement will be applied by the camera device.

FAST/HIGH_QUALITY both mean camera device determined enhancement will be applied. HIGH_QUALITY mode indicates that the camera device will use the highest-quality enhancement algorithms, even if it slows down capture rate. FAST means the camera device will not slow down capture rate when applying edge enhancement. FAST may be the same as OFF if edge enhancement will slow down capture rate. Every output stream will have a similar amount of enhancement applied.

ZERO_SHUTTER_LAG is meant to be used by applications that maintain a continuous circular buffer of high-resolution images during preview and reprocess image(s) from that buffer into a final capture when triggered by the user. In this mode, the camera device applies edge enhancement to low-resolution streams (below maximum recording resolution) to maximize preview quality, but does not apply edge enhancement to high-resolution streams, since those will be reprocessed later if necessary.

For YUV_REPROCESSING, these FAST/HIGH_QUALITY modes both mean that the camera device will apply FAST/HIGH_QUALITY YUV-domain edge enhancement, respectively. The camera device may adjust its internal edge enhancement parameters for best image quality based on the CaptureRequest#REPROCESS_EFFECTIVE_EXPOSURE_FACTOR, if it is set.

Possible values:

Available values for this device:
CameraCharacteristics#EDGE_AVAILABLE_EDGE_MODES

Optional - The value for this key may be null on some devices.

Full capability - Present on all camera devices that report being CameraCharacteristics#INFO_SUPPORTED_HARDWARE_LEVEL_FULL devices in the CameraCharacteristics#INFO_SUPPORTED_HARDWARE_LEVEL key

See also:

FLASH_MODE

public static final Key<Integer> FLASH_MODE

The desired mode for for the camera device's flash control.

This control is only effective when flash unit is available (CameraCharacteristics#FLASH_INFO_AVAILABLE == true).

When this control is used, the CaptureRequest#CONTROL_AE_MODE must be set to ON or OFF. Otherwise, the camera device auto-exposure related flash control (ON_AUTO_FLASH, ON_ALWAYS_FLASH, or ON_AUTO_FLASH_REDEYE) will override this control.

When set to OFF, the camera device will not fire flash for this capture.

When set to SINGLE, the camera device will fire flash regardless of the camera device's auto-exposure routine's result. When used in still capture case, this control should be used along with auto-exposure (AE) precapture metering sequence (CaptureRequest#CONTROL_AE_PRECAPTURE_TRIGGER), otherwise, the image may be incorrectly exposed.

When set to TORCH, the flash will be on continuously. This mode can be used for use cases such as preview, auto-focus assist, still capture, or video recording.

The flash status will be reported by CaptureResult#FLASH_STATE in the capture result metadata.

Possible values:

This key is available on all devices.

See also:

HOT_PIXEL_MODE

public static final Key<Integer> HOT_PIXEL_MODE

Operational mode for hot pixel correction.

Hotpixel correction interpolates out, or otherwise removes, pixels that do not accurately measure the incoming light (i.e. pixels that are stuck at an arbitrary value or are oversensitive).

Possible values:

Available values for this device:
CameraCharacteristics#HOT_PIXEL_AVAILABLE_HOT_PIXEL_MODES

Optional - The value for this key may be null on some devices.

See also:

JPEG_GPS_LOCATION

public static final Key<Location> JPEG_GPS_LOCATION

A location object to use when generating image GPS metadata.

Setting a location object in a request will include the GPS coordinates of the location into any JPEG images captured based on the request. These coordinates can then be viewed by anyone who receives the JPEG image.

This tag is also used for HEIC image capture.

This key is available on all devices.

JPEG_ORIENTATION

public static final Key<Integer> JPEG_ORIENTATION

The orientation for a JPEG image.

The clockwise rotation angle in degrees, relative to the orientation to the camera, that the JPEG picture needs to be rotated by, to be viewed upright.

Camera devices may either encode this value into the JPEG EXIF header, or rotate the image data to match this orientation. When the image data is rotated, the thumbnail data will also be rotated.

Note that this orientation is relative to the orientation of the camera sensor, given by CameraCharacteristics#SENSOR_ORIENTATION.

To translate from the device orientation given by the Android sensor APIs for camera sensors which are not EXTERNAL, the following sample code may be used:

private int getJpegOrientation(CameraCharacteristics c, int deviceOrientation) {
     if (deviceOrientation == android.view.OrientationEventListener.ORIENTATION_UNKNOWN) return 0;
     int sensorOrientation = c.get(CameraCharacteristics.SENSOR_ORIENTATION);

     // Round device orientation to a multiple of 90
     deviceOrientation = (deviceOrientation + 45) / 90 * 90;

     // Reverse device orientation for front-facing cameras
     boolean facingFront = c.get(CameraCharacteristics.LENS_FACING) == CameraCharacteristics.LENS_FACING_FRONT;
     if (facingFront) deviceOrientation = -deviceOrientation;

     // Calculate desired JPEG orientation relative to camera orientation to make
     // the image upright relative to the device orientation
     int jpegOrientation = (sensorOrientation + deviceOrientation + 360) % 360;

     return jpegOrientation;
 }
 

For EXTERNAL cameras the sensor orientation will always be set to 0 and the facing will also be set to EXTERNAL. The above code is not relevant in such case.

This tag is also used to describe the orientation of the HEIC image capture, in which case the rotation is reflected by EXIF orientation flag, and not by rotating the image data itself.

Units: Degrees in multiples of 90

Range of valid values:
0, 90, 180, 270

This key is available on all devices.

See also:

JPEG_QUALITY

public static final Key<Byte> JPEG_QUALITY

Compression quality of the final JPEG image.

85-95 is typical usage range. This tag is also used to describe the quality of the HEIC image capture.

Range of valid values:
1-100; larger is higher quality

This key is available on all devices.

JPEG_THUMBNAIL_QUALITY

public static final Key<Byte> JPEG_THUMBNAIL_QUALITY

Compression quality of JPEG thumbnail.

This tag is also used to describe the quality of the HEIC image capture.

Range of valid values:
1-100; larger is higher quality

This key is available on all devices.

JPEG_THUMBNAIL_SIZE

public static final Key<Size> JPEG_THUMBNAIL_SIZE

Resolution of embedded JPEG thumbnail.

When set to (0, 0) value, the JPEG EXIF will not contain thumbnail, but the captured JPEG will still be a valid image.

For best results, when issuing a request for a JPEG image, the thumbnail size selected should have the same aspect ratio as the main JPEG output.

If the thumbnail image aspect ratio differs from the JPEG primary image aspect ratio, the camera device creates the thumbnail by cropping it from the primary image. For example, if the primary image has 4:3 aspect ratio, the thumbnail image has 16:9 aspect ratio, the primary image will be cropped vertically (letterbox) to generate the thumbnail image. The thumbnail image will always have a smaller Field Of View (FOV) than the primary image when aspect ratios differ.

When an CaptureRequest#JPEG_ORIENTATION of non-zero degree is requested, the camera device will handle thumbnail rotation in one of the following ways:

  • Set the EXIF orientation flag and keep jpeg and thumbnail image data unrotated.
  • Rotate the jpeg and thumbnail image data and not set EXIF orientation flag. In this case, LIMITED or FULL hardware level devices will report rotated thumnail size in capture result, so the width and height will be interchanged if 90 or 270 degree orientation is requested. LEGACY device will always report unrotated thumbnail size.

The tag is also used as thumbnail size for HEIC image format capture, in which case the the thumbnail rotation is reflected by EXIF orientation flag, and not by rotating the thumbnail data itself.

Range of valid values:
CameraCharacteristics#JPEG_AVAILABLE_THUMBNAIL_SIZES

This key is available on all devices.

See also:

LENS_APERTURE

public static final Key<Float> LENS_APERTURE

The desired lens aperture size, as a ratio of lens focal length to the effective aperture diameter.

Setting this value is only supported on the camera devices that have a variable aperture lens.

When this is supported and CaptureRequest#CONTROL_AE_MODE is OFF, this can be set along with CaptureRequest#SENSOR_EXPOSURE_TIME, CaptureRequest#SENSOR_SENSITIVITY, and CaptureRequest#SENSOR_FRAME_DURATION to achieve manual exposure control.

The requested aperture value may take several frames to reach the requested value; the camera device will report the current (intermediate) aperture size in capture result metadata while the aperture is changing. While the aperture is still changing, CaptureResult#LENS_STATE will be set to MOVING.

When this is supported and CaptureRequest#CONTROL_AE_MODE is one of the ON modes, this will be overridden by the camera device auto-exposure algorithm, the overridden values are then provided back to the user in the corresponding result.

Units: The f-number (f/N)

Range of valid values:
CameraCharacteristics#LENS_INFO_AVAILABLE_APERTURES

Optional - The value for this key may be null on some devices.

Full capability - Present on all camera devices that report being CameraCharacteristics#INFO_SUPPORTED_HARDWARE_LEVEL_FULL devices in the CameraCharacteristics#INFO_SUPPORTED_HARDWARE_LEVEL key

See also:

LENS_FILTER_DENSITY

public static final Key<Float> LENS_FILTER_DENSITY

The desired setting for the lens neutral density filter(s).

This control will not be supported on most camera devices.

Lens filters are typically used to lower the amount of light the sensor is exposed to (measured in steps of EV). As used here, an EV step is the standard logarithmic representation, which are non-negative, and inversely proportional to the amount of light hitting the sensor. For example, setting this to 0 would result in no reduction of the incoming light, and setting this to 2 would mean that the filter is set to reduce incoming light by two stops (allowing 1/4 of the prior amount of light to the sensor).

It may take several frames before the lens filter density changes to the requested value. While the filter density is still changing, CaptureResult#LENS_STATE will be set to MOVING.

Units: Exposure Value (EV)

Range of valid values:
CameraCharacteristics#LENS_INFO_AVAILABLE_FILTER_DENSITIES

Optional - The value for this key may be null on some devices.

Full capability - Present on all camera devices that report being CameraCharacteristics#INFO_SUPPORTED_HARDWARE_LEVEL_FULL devices in the CameraCharacteristics#INFO_SUPPORTED_HARDWARE_LEVEL key

See also:

LENS_FOCAL_LENGTH

public static final Key<Float> LENS_FOCAL_LENGTH

The desired lens focal length; used for optical zoom.

This setting controls the physical focal length of the camera device's lens. Changing the focal length changes the field of view of the camera device, and is usually used for optical zoom.

Like CaptureRequest#LENS_FOCUS_DISTANCE and CaptureRequest#LENS_APERTURE, this setting won't be applied instantaneously, and it may take several frames before the lens can change to the requested focal length. While the focal length is still changing, CaptureResult#LENS_STATE will be set to MOVING.

Optical zoom via this control will not be supported on most devices. Starting from API level 30, the camera device may combine optical and digital zoom through the CaptureRequest#CONTROL_ZOOM_RATIO control.

Units: Millimeters

Range of valid values:
CameraCharacteristics#LENS_INFO_AVAILABLE_FOCAL_LENGTHS

This key is available on all devices.

See also:

LENS_FOCUS_DISTANCE

public static final Key<Float> LENS_FOCUS_DISTANCE

Desired distance to plane of sharpest focus, measured from frontmost surface of the lens.

This control can be used for setting manual focus, on devices that support the MANUAL_SENSOR capability and have a variable-focus lens (see CameraCharacteristics#LENS_INFO_MINIMUM_FOCUS_DISTANCE).

A value of 0.0f means infinity focus. The value set will be clamped to [0.0f, CameraCharacteristics#LENS_INFO_MINIMUM_FOCUS_DISTANCE].

Like CaptureRequest#LENS_FOCAL_LENGTH, this setting won't be applied instantaneously, and it may take several frames before the lens can move to the requested focus distance. While the lens is still moving, CaptureResult#LENS_STATE will be set to MOVING.

LEGACY devices support at most setting this to 0.0f for infinity focus.

Units: See CameraCharacteristics#LENS_INFO_FOCUS_DISTANCE_CALIBRATION for details

Range of valid values:
>= 0

Optional - The value for this key may be null on some devices.

Full capability - Present on all camera devices that report being CameraCharacteristics#INFO_SUPPORTED_HARDWARE_LEVEL_FULL devices in the CameraCharacteristics#INFO_SUPPORTED_HARDWARE_LEVEL key

See also:

LENS_OPTICAL_STABILIZATION_MODE

public static final Key<Integer> LENS_OPTICAL_STABILIZATION_MODE

Sets whether the camera device uses optical image stabilization (OIS) when capturing images.

OIS is used to compensate for motion blur due to small movements of the camera during capture. Unlike digital image stabilization (CaptureRequest#CONTROL_VIDEO_STABILIZATION_MODE), OIS makes use of mechanical elements to stabilize the camera sensor, and thus allows for longer exposure times before camera shake becomes apparent.

Switching between different optical stabilization modes may take several frames to initialize, the camera device will report the current mode in capture result metadata. For example, When "ON" mode is requested, the optical stabilization modes in the first several capture results may still be "OFF", and it will become "ON" when the initialization is done.

If a camera device supports both OIS and digital image stabilization (CaptureRequest#CONTROL_VIDEO_STABILIZATION_MODE), turning both modes on may produce undesirable interaction, so it is recommended not to enable both at the same time.

Not all devices will support OIS; see CameraCharacteristics#LENS_INFO_AVAILABLE_OPTICAL_STABILIZATION for available controls.

Possible values:

Available values for this device:
CameraCharacteristics#LENS_INFO_AVAILABLE_OPTICAL_STABILIZATION

Optional - The value for this key may be null on some devices.

Limited capability - Present on all camera devices that report being at least CameraCharacteristics#INFO_SUPPORTED_HARDWARE_LEVEL_LIMITED devices in the CameraCharacteristics#INFO_SUPPORTED_HARDWARE_LEVEL key

See also:

NOISE_REDUCTION_MODE

public static final Key<Integer> NOISE_REDUCTION_MODE

Mode of operation for the noise reduction algorithm.

The noise reduction algorithm attempts to improve image quality by removing excessive noise added by the capture process, especially in dark conditions.

OFF means no noise reduction will be applied by the camera device, for both raw and YUV domain.

MINIMAL means that only sensor raw domain basic noise reduction is enabled ,to remove demosaicing or other processing artifacts. For YUV_REPROCESSING, MINIMAL is same as OFF. This mode is optional, may not be support by all devices. The application should check CameraCharacteristics#NOISE_REDUCTION_AVAILABLE_NOISE_REDUCTION_MODES before using it.

FAST/HIGH_QUALITY both mean camera device determined noise filtering will be applied. HIGH_QUALITY mode indicates that the camera device will use the highest-quality noise filtering algorithms, even if it slows down capture rate. FAST means the camera device will not slow down capture rate when applying noise filtering. FAST may be the same as MINIMAL if MINIMAL is listed, or the same as OFF if any noise filtering will slow down capture rate. Every output stream will have a similar amount of enhancement applied.

ZERO_SHUTTER_LAG is meant to be used by applications that maintain a continuous circular buffer of high-resolution images during preview and reprocess image(s) from that buffer into a final capture when triggered by the user. In this mode, the camera device applies noise reduction to low-resolution streams (below maximum recording resolution) to maximize preview quality, but does not apply noise reduction to high-resolution streams, since those will be reprocessed later if necessary.

For YUV_REPROCESSING, these FAST/HIGH_QUALITY modes both mean that the camera device will apply FAST/HIGH_QUALITY YUV domain noise reduction, respectively. The camera device may adjust the noise reduction parameters for best image quality based on the CaptureRequest#REPROCESS_EFFECTIVE_EXPOSURE_FACTOR if it is set.

Possible values:

Available values for this device:
CameraCharacteristics#NOISE_REDUCTION_AVAILABLE_NOISE_REDUCTION_MODES

Optional - The value for this key may be null on some devices.

Full capability - Present on all camera devices that report being CameraCharacteristics#INFO_SUPPORTED_HARDWARE_LEVEL_FULL devices in the CameraCharacteristics#INFO_SUPPORTED_HARDWARE_LEVEL key

See also:

REPROCESS_EFFECTIVE_EXPOSURE_FACTOR

public static final Key<Float> REPROCESS_EFFECTIVE_EXPOSURE_FACTOR

The amount of exposure time increase factor applied to the original output frame by the application processing before sending for reprocessing.

This is optional, and will be supported if the camera device supports YUV_REPROCESSING capability (CameraCharacteristics#REQUEST_AVAILABLE_CAPABILITIES contains YUV_REPROCESSING).

For some YUV reprocessing use cases, the application may choose to filter the original output frames to effectively reduce the noise to the same level as a frame that was captured with longer exposure time. To be more specific, assuming the original captured images were captured with a sensitivity of S and an exposure time of T, the model in the camera device is that the amount of noise in the image would be approximately what would be expected if the original capture parameters had been a sensitivity of S/effectiveExposureFactor and an exposure time of T*effectiveExposureFactor, rather than S and T respectively. If the captured images were processed by the application before being sent for reprocessing, then the application may have used image processing algorithms and/or multi-frame image fusion to reduce the noise in the application-processed images (input images). By using the effectiveExposureFactor control, the application can communicate to the camera device the actual noise level improvement in the application-processed image. With this information, the camera device can select appropriate noise reduction and edge enhancement parameters to avoid excessive noise reduction (CaptureRequest#NOISE_REDUCTION_MODE) and insufficient edge enhancement (CaptureRequest#EDGE_MODE) being applied to the reprocessed frames.

For example, for multi-frame image fusion use case, the application may fuse multiple output frames together to a final frame for reprocessing. When N image are fused into 1 image for reprocessing, the exposure time increase factor could be up to square root of N (based on a simple photon shot noise model). The camera device will adjust the reprocessing noise reduction and edge enhancement parameters accordingly to produce the best quality images.

This is relative factor, 1.0 indicates the application hasn't processed the input buffer in a way that affects its effective exposure time.

This control is only effective for YUV reprocessing capture request. For noise reduction reprocessing, it is only effective when CaptureRequest#NOISE_REDUCTION_MODE != OFF. Similarly, for edge enhancement reprocessing, it is only effective when CaptureRequest#EDGE_MODE != OFF.

Units: Relative exposure time increase factor.

Range of valid values:
>= 1.0

Optional - The value for this key may be null on some devices.

Limited capability - Present on all camera devices that report being at least CameraCharacteristics#INFO_SUPPORTED_HARDWARE_LEVEL_LIMITED devices in the CameraCharacteristics#INFO_SUPPORTED_HARDWARE_LEVEL key

See also:

SCALER_CROP_REGION

public static final Key<Rect> SCALER_CROP_REGION

The desired region of the sensor to read out for this capture.

This control can be used to implement digital zoom.

For devices not supporting CaptureRequest#DISTORTION_CORRECTION_MODE control, the coordinate system always follows that of CameraCharacteristics#SENSOR_INFO_ACTIVE_ARRAY_SIZE, with (0, 0) being the top-left pixel of the active array.

For devices supporting CaptureRequest#DISTORTION_CORRECTION_MODE control, the coordinate system depends on the mode being set. When the distortion correction mode is OFF, the coordinate system follows CameraCharacteristics#SENSOR_INFO_PRE_CORRECTION_ACTIVE_ARRAY_SIZE, with (0, 0) being the top-left pixel of the pre-correction active array. When the distortion correction mode is not OFF, the coordinate system follows CameraCharacteristics#SENSOR_INFO_ACTIVE_ARRAY_SIZE, with (0, 0) being the top-left pixel of the active array.

Output streams use this rectangle to produce their output, cropping to a smaller region if necessary to maintain the stream's aspect ratio, then scaling the sensor input to match the output's configured resolution.

The crop region is applied after the RAW to other color space (e.g. YUV) conversion. Since raw streams (e.g. RAW16) don't have the conversion stage, they are not croppable. The crop region will be ignored by raw streams.

For non-raw streams, any additional per-stream cropping will be done to maximize the final pixel area of the stream.

For example, if the crop region is set to a 4:3 aspect ratio, then 4:3 streams will use the exact crop region. 16:9 streams will further crop vertically (letterbox).

Conversely, if the crop region is set to a 16:9, then 4:3 outputs will crop horizontally (pillarbox), and 16:9 streams will match exactly. These additional crops will be centered within the crop region.

To illustrate, here are several scenarios of different crop regions and output streams, for a hypothetical camera device with an active array of size (2000,1500). Note that several of these examples use non-centered crop regions for ease of illustration; such regions are only supported on devices with FREEFORM capability (CameraCharacteristics#SCALER_CROPPING_TYPE == FREEFORM), but this does not affect the way the crop rules work otherwise.

  • Camera Configuration:
    • Active array size: 2000x1500 (3 MP, 4:3 aspect ratio)
    • Output stream #1: 640x480 (VGA, 4:3 aspect ratio)
    • Output stream #2: 1280x720 (720p, 16:9 aspect ratio)
  • Case #1: 4:3 crop region with 2x digital zoom
    • Crop region: Rect(500, 375, 1500, 1125) // (left, top, right, bottom)
    • 4:3 aspect ratio crop diagram
    • 640x480 stream source area: (500, 375, 1500, 1125) (equal to crop region)
    • 1280x720 stream source area: (500, 469, 1500, 1031) (letterboxed)
  • Case #2: 16:9 crop region with ~1.5x digital zoom.
    • Crop region: Rect(500, 375, 1833, 1125)
    • 16:9 aspect ratio crop diagram
    • 640x480 stream source area: (666, 375, 1666, 1125) (pillarboxed)
    • 1280x720 stream source area: (500, 375, 1833, 1125) (equal to crop region)
  • Case #3: 1:1 crop region with ~2.6x digital zoom.
    • Crop region: Rect(500, 375, 1250, 1125)
    • 1:1 aspect ratio crop diagram
    • 640x480 stream source area: (500, 469, 1250, 1031) (letterboxed)
    • 1280x720 stream source area: (500, 543, 1250, 957) (letterboxed)
  • Case #4: Replace 640x480 stream with 1024x1024 stream, with 4:3 crop region:
    • Crop region: Rect(500, 375, 1500, 1125)
    • Square output, 4:3 aspect ratio crop diagram
    • 1024x1024 stream source area: (625, 375, 1375, 1125) (pillarboxed)
    • 1280x720 stream source area: (500, 469, 1500, 1031) (letterboxed)
    • Note that in this case, neither of the two outputs is a subset of the other, with each containing image data the other doesn't have.

If the coordinate system is CameraCharacteristics#SENSOR_INFO_ACTIVE_ARRAY_SIZE, the width and height of the crop region cannot be set to be smaller than floor( activeArraySize.width / CameraCharacteristics#SCALER_AVAILABLE_MAX_DIGITAL_ZOOM ) and floor( activeArraySize.height / CameraCharacteristics#SCALER_AVAILABLE_MAX_DIGITAL_ZOOM ), respectively.

If the coordinate system is CameraCharacteristics#SENSOR_INFO_PRE_CORRECTION_ACTIVE_ARRAY_SIZE, the width and height of the crop region cannot be set to be smaller than floor( preCorrectionActiveArraySize.width / CameraCharacteristics#SCALER_AVAILABLE_MAX_DIGITAL_ZOOM ) and floor( preCorrectionActiveArraySize.height / CameraCharacteristics#SCALER_AVAILABLE_MAX_DIGITAL_ZOOM ), respectively.

The camera device may adjust the crop region to account for rounding and other hardware requirements; the final crop region used will be included in the output capture result.

Starting from API level 30, it's strongly recommended to use CaptureRequest#CONTROL_ZOOM_RATIO to take advantage of better support for zoom with logical multi-camera. The benefits include better precision with optical-digital zoom combination, and ability to do zoom-out from 1.0x. When using CaptureRequest#CONTROL_ZOOM_RATIO for zoom, the crop region in the capture request must be either letterboxing or pillarboxing (but not both). The coordinate system is post-zoom, meaning that the activeArraySize or preCorrectionActiveArraySize covers the camera device's field of view "after" zoom. See CaptureRequest#CONTROL_ZOOM_RATIO for details.

Units: Pixel coordinates relative to CameraCharacteristics#SENSOR_INFO_ACTIVE_ARRAY_SIZE or CameraCharacteristics#SENSOR_INFO_PRE_CORRECTION_ACTIVE_ARRAY_SIZE depending on distortion correction capability and mode

This key is available on all devices.

See also:

SENSOR_EXPOSURE_TIME

public static final Key<Long> SENSOR_EXPOSURE_TIME

Duration each pixel is exposed to light.

If the sensor can't expose this exact duration, it will shorten the duration exposed to the nearest possible value (rather than expose longer). The final exposure time used will be available in the output capture result.

This control is only effective if CaptureRequest#CONTROL_AE_MODE or CaptureRequest#CONTROL_MODE is set to OFF; otherwise the auto-exposure algorithm will override this value.

Units: Nanoseconds

Range of valid values:
CameraCharacteristics#SENSOR_INFO_EXPOSURE_TIME_RANGE

Optional - The value for this key may be null on some devices.

Full capability - Present on all camera devices that report being CameraCharacteristics#INFO_SUPPORTED_HARDWARE_LEVEL_FULL devices in the CameraCharacteristics#INFO_SUPPORTED_HARDWARE_LEVEL key

See also:

SENSOR_FRAME_DURATION

public static final Key<Long> SENSOR_FRAME_DURATION

Duration from start of frame exposure to start of next frame exposure.

The maximum frame rate that can be supported by a camera subsystem is a function of many factors:

  • Requested resolutions of output image streams
  • Availability of binning / skipping modes on the imager
  • The bandwidth of the imager interface
  • The bandwidth of the various ISP processing blocks

Since these factors can vary greatly between different ISPs and sensors, the camera abstraction tries to represent the bandwidth restrictions with as simple a model as possible.

The model presented has the following characteristics:

  • The image sensor is always configured to output the smallest resolution possible given the application's requested output stream sizes. The smallest resolution is defined as being at least as large as the largest requested output stream size; the camera pipeline must never digitally upsample sensor data when the crop region covers the whole sensor. In general, this means that if only small output stream resolutions are configured, the sensor can provide a higher frame rate.
  • Since any request may use any or all the currently configured output streams, the sensor and ISP must be configured to support scaling a single capture to all the streams at the same time. This means the camera pipeline must be ready to produce the largest requested output size without any delay. Therefore, the overall frame rate of a given configured stream set is governed only by the largest requested stream resolution.
  • Using more than one output stream in a request does not affect the frame duration.
  • Certain format-streams may need to do additional background processing before data is consumed/produced by that stream. These processors can run concurrently to the rest of the camera pipeline, but cannot process more than 1 capture at a time.

The necessary information for the application, given the model above, is provided via StreamConfigurationMap.getOutputMinFrameDuration(int, Size). These are used to determine the maximum frame rate / minimum frame duration that is possible for a given stream configuration.

Specifically, the application can use the following rules to determine the minimum frame duration it can request from the camera device:

  1. Let the set of currently configured input/output streams be called S.
  2. Find the minimum frame durations for each stream in S, by looking it up in StreamConfigurationMap.getOutputMinFrameDuration(int, Size) (with its respective size/format). Let this set of frame durations be called F.
  3. For any given request R, the minimum frame duration allowed for R is the maximum out of all values in F. Let the streams used in R be called S_r.

If none of the streams in S_r have a stall time (listed in StreamConfigurationMap.getOutputStallDuration(int, Size) using its respective size/format), then the frame duration in F determines the steady state frame rate that the application will get if it uses R as a repeating request. Let this special kind of request be called Rsimple.

A repeating request Rsimple can be occasionally interleaved by a single capture of a new request Rstall (which has at least one in-use stream with a non-0 stall time) and if Rstall has the same minimum frame duration this will not cause a frame rate loss if all buffers from the previous Rstall have already been delivered.

For more details about stalling, see StreamConfigurationMap.getOutputStallDuration(int, Size).

This control is only effective if CaptureRequest#CONTROL_AE_MODE or CaptureRequest#CONTROL_MODE is set to OFF; otherwise the auto-exposure algorithm will override this value.

Units: Nanoseconds

Range of valid values:
See CameraCharacteristics#SENSOR_INFO_MAX_FRAME_DURATION, StreamConfigurationMap. The duration is capped to max(duration, exposureTime + overhead).

Optional - The value for this key may be null on some devices.

Full capability - Present on all camera devices that report being CameraCharacteristics#INFO_SUPPORTED_HARDWARE_LEVEL_FULL devices in the CameraCharacteristics#INFO_SUPPORTED_HARDWARE_LEVEL key

See also:

SENSOR_SENSITIVITY

public static final Key<Integer> SENSOR_SENSITIVITY

The amount of gain applied to sensor data before processing.

The sensitivity is the standard ISO sensitivity value, as defined in ISO 12232:2006.

The sensitivity must be within CameraCharacteristics#SENSOR_INFO_SENSITIVITY_RANGE, and if if it less than CameraCharacteristics#SENSOR_MAX_ANALOG_SENSITIVITY, the camera device is guaranteed to use only analog amplification for applying the gain.

If the camera device cannot apply the exact sensitivity requested, it will reduce the gain to the nearest supported value. The final sensitivity used will be available in the output capture result.

This control is only effective if CaptureRequest#CONTROL_AE_MODE or CaptureRequest#CONTROL_MODE is set to OFF; otherwise the auto-exposure algorithm will override this value.

Note that for devices supporting postRawSensitivityBoost, the total sensitivity applied to the final processed image is the combination of CaptureRequest#SENSOR_SENSITIVITY and CaptureRequest#CONTROL_POST_RAW_SENSITIVITY_BOOST. In case the application uses the sensor sensitivity from last capture result of an auto request for a manual request, in order to achieve the same brightness in the output image, the application should also set postRawSensitivityBoost.

Units: ISO arithmetic units

Range of valid values:
CameraCharacteristics#SENSOR_INFO_SENSITIVITY_RANGE

Optional - The value for this key may be null on some devices.

Full capability - Present on all camera devices that report being CameraCharacteristics#INFO_SUPPORTED_HARDWARE_LEVEL_FULL devices in the CameraCharacteristics#INFO_SUPPORTED_HARDWARE_LEVEL key

See also:

SENSOR_TEST_PATTERN_DATA

public static final Key<int[]> SENSOR_TEST_PATTERN_DATA

A pixel [R, G_even, G_odd, B] that supplies the test pattern when CaptureRequest#SENSOR_TEST_PATTERN_MODE is SOLID_COLOR.

Each color channel is treated as an unsigned 32-bit integer. The camera device then uses the most significant X bits that correspond to how many bits are in its Bayer raw sensor output.

For example, a sensor with RAW10 Bayer output would use the 10 most significant bits from each color channel.

Optional - The value for this key may be null on some devices.

See also:

SENSOR_TEST_PATTERN_MODE

public static final Key<Integer> SENSOR_TEST_PATTERN_MODE

When enabled, the sensor sends a test pattern instead of doing a real exposure from the camera.

When a test pattern is enabled, all manual sensor controls specified by android.sensor.* will be ignored. All other controls should work as normal.

For example, if manual flash is enabled, flash firing should still occur (and that the test pattern remain unmodified, since the flash would not actually affect it).

Defaults to OFF.

Possible values:

Available values for this device:
CameraCharacteristics#SENSOR_AVAILABLE_TEST_PATTERN_MODES

Optional - The value for this key may be null on some devices.

See also:

SHADING_MODE

public static final Key<Integer> SHADING_MODE

Quality of lens shading correction applied to the image data.

When set to OFF mode, no lens shading correction will be applied by the camera device, and an identity lens shading map data will be provided if CaptureRequest#STATISTICS_LENS_SHADING_MAP_MODE == ON. For example, for lens shading map with size of [ 4, 3 ], the output CaptureResult#STATISTICS_LENS_SHADING_CORRECTION_MAP for this case will be an identity map shown below:

[ 1.0, 1.0, 1.0, 1.0,  1.0, 1.0, 1.0, 1.0,
  1.0, 1.0, 1.0, 1.0,  1.0, 1.0, 1.0, 1.0,
  1.0, 1.0, 1.0, 1.0,  1.0, 1.0, 1.0, 1.0,
  1.0, 1.0, 1.0, 1.0,  1.0, 1.0, 1.0, 1.0,
  1.0, 1.0, 1.0, 1.0,  1.0, 1.0, 1.0, 1.0,
  1.0, 1.0, 1.0, 1.0,  1.0, 1.0, 1.0, 1.0 ]
 

When set to other modes, lens shading correction will be applied by the camera device. Applications can request lens shading map data by setting CaptureRequest#STATISTICS_LENS_SHADING_MAP_MODE to ON, and then the camera device will provide lens shading map data in CaptureResult#STATISTICS_LENS_SHADING_CORRECTION_MAP; the returned shading map data will be the one applied by the camera device for this capture request.

The shading map data may depend on the auto-exposure (AE) and AWB statistics, therefore the reliability of the map data may be affected by the AE and AWB algorithms. When AE and AWB are in AUTO modes(CaptureRequest#CONTROL_AE_MODE != OFF and CaptureRequest#CONTROL_AWB_MODE != OFF), to get best results, it is recommended that the applications wait for the AE and AWB to be converged before using the returned shading map data.

Possible values:

Available values for this device:
CameraCharacteristics#SHADING_AVAILABLE_MODES

Optional - The value for this key may be null on some devices.

Full capability - Present on all camera devices that report being CameraCharacteristics#INFO_SUPPORTED_HARDWARE_LEVEL_FULL devices in the CameraCharacteristics#INFO_SUPPORTED_HARDWARE_LEVEL key

See also:

STATISTICS_FACE_DETECT_MODE

public static final Key<Integer> STATISTICS_FACE_DETECT_MODE

Operating mode for the face detector unit.

Whether face detection is enabled, and whether it should output just the basic fields or the full set of fields.

Possible values:

Available values for this device:
CameraCharacteristics#STATISTICS_INFO_AVAILABLE_FACE_DETECT_MODES

This key is available on all devices.

See also:

STATISTICS_HOT_PIXEL_MAP_MODE

public static final Key<Boolean> STATISTICS_HOT_PIXEL_MAP_MODE

Operating mode for hot pixel map generation.

If set to true, a hot pixel map is returned in CaptureResult#STATISTICS_HOT_PIXEL_MAP. If set to false, no hot pixel map will be returned.

Range of valid values:
CameraCharacteristics#STATISTICS_INFO_AVAILABLE_HOT_PIXEL_MAP_MODES

Optional - The value for this key may be null on some devices.

See also:

STATISTICS_LENS_SHADING_MAP_MODE

public static final Key<Integer> STATISTICS_LENS_SHADING_MAP_MODE

Whether the camera device will output the lens shading map in output result metadata.

When set to ON, android.statistics.lensShadingMap will be provided in the output result metadata.

ON is always supported on devices with the RAW capability.

Possible values:

Available values for this device:
CameraCharacteristics#STATISTICS_INFO_AVAILABLE_LENS_SHADING_MAP_MODES

Optional - The value for this key may be null on some devices.

Full capability - Present on all camera devices that report being CameraCharacteristics#INFO_SUPPORTED_HARDWARE_LEVEL_FULL devices in the CameraCharacteristics#INFO_SUPPORTED_HARDWARE_LEVEL key

See also:

STATISTICS_OIS_DATA_MODE

public static final Key<Integer> STATISTICS_OIS_DATA_MODE

A control for selecting whether optical stabilization (OIS) position information is included in output result metadata.

Since optical image stabilization generally involves motion much faster than the duration of individualq image exposure, multiple OIS samples can be included for a single capture result. For example, if the OIS reporting operates at 200 Hz, a typical camera operating at 30fps may have 6-7 OIS samples per capture result. This information can be combined with the rolling shutter skew to account for lens motion during image exposure in post-processing algorithms.

Possible values:

Available values for this device:
CameraCharacteristics#STATISTICS_INFO_AVAILABLE_OIS_DATA_MODES

Optional - The value for this key may be null on some devices.

See also:

TONEMAP_CURVE

public static final Key<TonemapCurve> TONEMAP_CURVE

Tonemapping / contrast / gamma curve to use when CaptureRequest#TONEMAP_MODE is CONTRAST_CURVE.

The tonemapCurve consist of three curves for each of red, green, and blue channels respectively. The following example uses the red channel as an example. The same logic applies to green and blue channel. Each channel's curve is defined by an array of control points:

curveRed =
   [ P0(in, out), P1(in, out), P2(in, out), P3(in, out), ..., PN(in, out) ]
 2 <= N <= CameraCharacteristics#TONEMAP_MAX_CURVE_POINTS

These are sorted in order of increasing Pin; it is always guaranteed that input values 0.0 and 1.0 are included in the list to define a complete mapping. For input values between control points, the camera device must linearly interpolate between the control points.

Each curve can have an independent number of points, and the number of points can be less than max (that is, the request doesn't have to always provide a curve with number of points equivalent to CameraCharacteristics#TONEMAP_MAX_CURVE_POINTS).

For devices with MONOCHROME capability, all three channels must have the same set of control points.

A few examples, and their corresponding graphical mappings; these only specify the red channel and the precision is limited to 4 digits, for conciseness.

Linear mapping:

curveRed = [ (0, 0), (1.0, 1.0) ]
 

Linear mapping curve

Invert mapping:

curveRed = [ (0, 1.0), (1.0, 0) ]
 

Inverting mapping curve

Gamma 1/2.2 mapping, with 16 control points:

curveRed = [
   (0.0000, 0.0000), (0.0667, 0.2920), (0.1333, 0.4002), (0.2000, 0.4812),
   (0.2667, 0.5484), (0.3333, 0.6069), (0.4000, 0.6594), (0.4667, 0.7072),
   (0.5333, 0.7515), (0.6000, 0.7928), (0.6667, 0.8317), (0.7333, 0.8685),
   (0.8000, 0.9035), (0.8667, 0.9370), (0.9333, 0.9691), (1.0000, 1.0000) ]
 

Gamma = 1/2.2 tonemapping curve

Standard sRGB gamma mapping, per IEC 61966-2-1:1999, with 16 control points:

curveRed = [
   (0.0000, 0.0000), (0.0667, 0.2864), (0.1333, 0.4007), (0.2000, 0.4845),
   (0.2667, 0.5532), (0.3333, 0.6125), (0.4000, 0.6652), (0.4667, 0.7130),
   (0.5333, 0.7569), (0.6000, 0.7977), (0.6667, 0.8360), (0.7333, 0.8721),
   (0.8000, 0.9063), (0.8667, 0.9389), (0.9333, 0.9701), (1.0000, 1.0000) ]
 

sRGB tonemapping curve

Optional - The value for this key may be null on some devices.

Full capability - Present on all camera devices that report being CameraCharacteristics#INFO_SUPPORTED_HARDWARE_LEVEL_FULL devices in the CameraCharacteristics#INFO_SUPPORTED_HARDWARE_LEVEL key

See also:

TONEMAP_GAMMA

public static final Key<Float> TONEMAP_GAMMA

Tonemapping curve to use when CaptureRequest#TONEMAP_MODE is GAMMA_VALUE

The tonemap curve will be defined the following formula: * OUT = pow(IN, 1.0 / gamma) where IN and OUT is the input pixel value scaled to range [0.0, 1.0], pow is the power function and gamma is the gamma value specified by this key.

The same curve will be applied to all color channels. The camera device may clip the input gamma value to its supported range. The actual applied value will be returned in capture result.

The valid range of gamma value varies on different devices, but values within [1.0, 5.0] are guaranteed not to be clipped.

Optional - The value for this key may be null on some devices.

See also:

TONEMAP_MODE

public static final Key<Integer> TONEMAP_MODE

High-level global contrast/gamma/tonemapping control.

When switching to an application-defined contrast curve by setting CaptureRequest#TONEMAP_MODE to CONTRAST_CURVE, the curve is defined per-channel with a set of (in, out) points that specify the mapping from input high-bit-depth pixel value to the output low-bit-depth value. Since the actual pixel ranges of both input and output may change depending on the camera pipeline, the values are specified by normalized floating-point numbers.

More-complex color mapping operations such as 3D color look-up tables, selective chroma enhancement, or other non-linear color transforms will be disabled when CaptureRequest#TONEMAP_MODE is CONTRAST_CURVE.

When using either FAST or HIGH_QUALITY, the camera device will emit its own tonemap curve in CaptureRequest#TONEMAP_CURVE. These values are always available, and as close as possible to the actually used nonlinear/nonglobal transforms.

If a request is sent with CONTRAST_CURVE with the camera device's provided curve in FAST or HIGH_QUALITY, the image's tonemap will be roughly the same.

Possible values:

Available values for this device:
CameraCharacteristics#TONEMAP_AVAILABLE_TONE_MAP_MODES

Optional - The value for this key may be null on some devices.

Full capability - Present on all camera devices that report being CameraCharacteristics#INFO_SUPPORTED_HARDWARE_LEVEL_FULL devices in the CameraCharacteristics#INFO_SUPPORTED_HARDWARE_LEVEL key

See also:

TONEMAP_PRESET_CURVE

public static final Key<Integer> TONEMAP_PRESET_CURVE

Tonemapping curve to use when CaptureRequest#TONEMAP_MODE is PRESET_CURVE

The tonemap curve will be defined by specified standard.

sRGB (approximated by 16 control points):

sRGB tonemapping curve

Rec. 709 (approximated by 16 control points):

Rec. 709 tonemapping curve

Note that above figures show a 16 control points approximation of preset curves. Camera devices may apply a different approximation to the curve.

Possible values:

Optional - The value for this key may be null on some devices.

See also:

Public methods

describeContents

public int describeContents ()

Describe the kinds of special objects contained in this Parcelable instance's marshaled representation. For example, if the object will include a file descriptor in the output of writeToParcel(android.os.Parcel, int), the return value of this method must include the CONTENTS_FILE_DESCRIPTOR bit.

Returns
int a bitmask indicating the set of special object types marshaled by this Parcelable object instance. Value is either 0 or CONTENTS_FILE_DESCRIPTOR

equals

public boolean equals (Object other)

Determine whether this CaptureRequest is equal to another CaptureRequest.

A request is considered equal to another is if it's set of key/values is equal, it's list of output surfaces is equal, the user tag is equal, and the return values of isReprocess() are equal.

Parameters
other Object: Another instance of CaptureRequest.

Returns
boolean True if the requests are the same, false otherwise.

get

public T get (Key<T> key)

Get a capture request field value.

The field definitions can be found in CaptureRequest.

Querying the value for the same key more than once will return a value which is equal to the previous queried value.

Parameters
key Key: The result field to read.

Returns
T The value of that key, or null if the field is not set.

Throws
IllegalArgumentException if the key was not valid

getKeys

public List<Key<?>> getKeys ()

Returns a list of the keys contained in this map.

The list returned is not modifiable, so any attempts to modify it will throw a UnsupportedOperationException.

All values retrieved by a key from this list with #get are guaranteed to be non-null. Each key is only listed once in the list. The order of the keys is undefined.

Returns
List<Key<?>> This value cannot be null.

getTag

public Object getTag ()

Retrieve the tag for this request, if any.

This tag is not used for anything by the camera device, but can be used by an application to easily identify a CaptureRequest when it is returned by CameraCaptureSession.CaptureCallback#onCaptureCompleted

Returns
Object the last tag Object set on this request, or null if no tag has been set.

See also:

hashCode

public int hashCode ()

Returns a hash code value for the object. This method is supported for the benefit of hash tables such as those provided by HashMap.

The general contract of hashCode is:

  • Whenever it is invoked on the same object more than once during an execution of a Java application, the hashCode method must consistently return the same integer, provided no information used in equals comparisons on the object is modified. This integer need not remain consistent from one execution of an application to another execution of the same application.
  • If two objects are equal according to the equals(Object) method, then calling the hashCode method on each of the two objects must produce the same integer result.
  • It is not required that if two objects are unequal according to the equals(java.lang.Object) method, then calling the hashCode method on each of the two objects must produce distinct integer results. However, the programmer should be aware that producing distinct integer results for unequal objects may improve the performance of hash tables.

As much as is reasonably practical, the hashCode method defined by class Object does return distinct integers for distinct objects. (This is typically implemented by converting the internal address of the object into an integer, but this implementation technique is not required by the Java™ programming language.)

Returns
int a hash code value for this object.

isReprocess

public boolean isReprocess ()

Determine if this is a reprocess capture request.

A reprocess capture request produces output images from an input buffer from the CameraCaptureSession's input Surface. A reprocess capture request can be created by CameraDevice#createReprocessCaptureRequest.

Returns
boolean true if this is a reprocess capture request. false if this is not a reprocess capture request.

See also:

writeToParcel

public void writeToParcel (Parcel dest, 
                int flags)

Flatten this object in to a Parcel.

Parameters
dest Parcel: The Parcel in which the object should be written.

flags int: Additional flags about how the object should be written. May be 0 or Parcelable.PARCELABLE_WRITE_RETURN_VALUE. Value is either 0 or a combination of Parcelable.PARCELABLE_WRITE_RETURN_VALUE, and android.os.Parcelable.PARCELABLE_ELIDE_DUPLICATES