Module libcamera::controls

source ·

Structs§

  • Enable or disable the AE.
  • Report the lock status of a running AE algorithm.
  • Sets the focus windows used by the AF algorithm when AfMetering is set to AfMeteringWindows. The units used are pixels within the rectangle returned by the ScalerCropMaximum property.
  • Analogue gain value applied in the sensor device. The value of the control specifies the gain multiplier applied to all colour channels. This value cannot be lower than 1.0.
  • Enable or disable the AWB.
  • Report the lock status of a running AWB algorithm.
  • Specify a fixed brightness parameter. Positive values (up to 1.0) produce brighter images; negative values (up to -1.0) produce darker images and 0.0 leaves pixels unchanged.
  • The 3x3 matrix that converts camera RGB to sRGB within the imaging pipeline. This should describe the matrix that is used after pixels have been white-balanced, but before any gamma transformation. The 3x3 matrix is stored in conventional reading order in an array of 9 floating point values.
  • Pair of gain values for the Red and Blue colour channels, in that order. ColourGains can only be applied in a Request when the AWB is disabled.
  • Report the current estimate of the colour temperature, in kelvin, for this frame. The ColourTemperature control can only be returned in metadata.
  • Specify a fixed contrast parameter. Normal contrast is given by the value 1.0; larger values produce images with more contrast.
  • Digital gain value applied during the processing steps applied to the image as captured from the sensor.
  • Exposure time (shutter speed) for the frame applied in the sensor device. This value is specified in micro-seconds.
  • Specify an Exposure Value (EV) parameter. The EV parameter will only be applied if the AE algorithm is currently enabled.
  • Reports a Figure of Merit (FoM) to indicate how in-focus the frame is. A larger FocusFoM value indicates a more in-focus frame. This singular value may be based on a combination of statistics gathered from multiple focus regions within an image. The number of focus regions and method of combination is platform dependent. In this respect, it is not necessarily aimed at providing a way to implement a focus algorithm by the application, rather an indication of how in-focus a frame is.
  • The instantaneous frame duration from start of frame exposure to start of next exposure, expressed in microseconds. This control is meant to be returned in metadata.
  • The minimum and maximum (in that order) frame duration, expressed in microseconds.
  • Acts as a control to instruct the lens to move to a particular position and also reports back the position of the lens for each frame.
  • Report an estimate of the current illuminance level in lux. The Lux control can only be returned in metadata.
  • The maximum number of frames that can occur after a request (different than the previous) has been submitted, and before the result’s state becomes synchronized. A value of -1 indicates unknown latency, and 0 indicates per-frame control. Currently identical to ANDROID_SYNC_MAX_LATENCY.
  • Specifies the number of pipeline stages the frame went through from when it was exposed to when the final completed result was available to the framework. Always less than or equal to PipelineMaxDepth. Currently identical to ANDROID_REQUEST_PIPELINE_DEPTH.
  • Specify a fixed saturation parameter. Normal saturation is given by the value 1.0; larger values produce more saturated colours; 0.0 produces a greyscale image.
  • Sets the image portion that will be scaled to form the whole of the final output image. The (x,y) location of this rectangle is relative to the PixelArrayActiveAreas that is being used. The units remain native sensor pixels, even if the sensor is being used in a binning or skipping mode.
  • Reports the sensor black levels used for processing a frame, in the order R, Gr, Gb, B. These values are returned as numbers out of a 16-bit pixel range (as if pixels ranged from 0 to 65535). The SensorBlackLevels control can only be returned in metadata.
  • Control to report the time between the start of exposure of the first row and the start of exposure of the last row. Currently identical to ANDROID_SENSOR_ROLLING_SHUTTER_SKEW
  • Temperature measure from the camera sensor in Celsius. This is typically obtained by a thermal sensor present on-die or in the camera module. The range of reported temperatures is device dependent.
  • The time when the first row of the image sensor active array is exposed.
  • A value of 0.0 means no sharpening. The minimum value means minimal sharpening, and shall be 0.0 unless the camera can’t disable sharpening completely. The default value shall give a “reasonable” level of sharpening, suitable for most use cases. The maximum value may apply extremely high levels of sharpening, higher than anyone could reasonably want. Negative values are not allowed. Note also that sharpening is not applied to raw streams.

Enums§

  • Specify a constraint mode for the AE algorithm to use. These determine how the measured scene brightness is adjusted to reach the desired target exposure. Constraint modes may be platform specific, and not all constraint modes may be supported.
  • Specify an exposure mode for the AE algorithm to use. These specify how the desired total exposure is divided between the shutter time and the sensor’s analogue gain. The exposure modes are platform specific, and not all exposure modes may be supported.
  • Specify a metering mode for the AE algorithm to use. The metering modes determine which parts of the image are used to determine the scene brightness. Metering modes may be platform specific and not all metering modes may be supported.
  • Control for AE metering trigger. Currently identical to ANDROID_CONTROL_AE_PRECAPTURE_TRIGGER.
  • Control to report the current AE algorithm state. Currently identical to ANDROID_CONTROL_AE_STATE.
  • Instruct the AF algorithm how it should decide which parts of the image should be used to measure focus.
  • Control to set the mode of the AF (autofocus) algorithm.
  • This control has no effect except when in continuous autofocus mode (AfModeContinuous). It can be used to pause any lens movements while (for example) images are captured. The algorithm remains inactive until it is instructed to resume.
  • Only applicable in continuous (AfModeContinuous) mode, this reports whether the algorithm is currently running, paused or pausing (that is, will pause as soon as any in-progress scan completes).
  • Control to set the range of focus distances that is scanned. An implementation may choose not to implement all the options here.
  • Control that determines whether the AF algorithm is to move the lens as quickly as possible or more steadily. For example, during video recording it may be desirable not to move the lens too abruptly, but when in a preview mode (waiting for a still capture) it may be helpful to move the lens as quickly as is reasonably possible.
  • Reports the current state of the AF algorithm in conjunction with the reported AfMode value and (in continuous AF mode) the AfPauseState value. The possible state changes are described below, though we note the following state transitions that occur when the AfMode is changed.
  • This control starts an autofocus scan when AfMode is set to AfModeAuto, and can also be used to terminate a scan early.
  • Specify the range of illuminants to use for the AWB algorithm. The modes supported are platform specific, and not all modes may be supported.
  • Control to report the current AWB algorithm state. Currently identical to ANDROID_CONTROL_AWB_STATE.
  • Control to select the color correction aberration mode. Currently identical to ANDROID_COLOR_CORRECTION_ABERRATION_MODE.
  • Control to report if the lens shading map is available. Currently identical to ANDROID_STATISTICS_LENS_SHADING_MAP_MODE.
  • Control to select the noise reduction algorithm mode. Currently identical to ANDROID_NOISE_REDUCTION_MODE.
  • Control to report the detected scene light frequency. Currently identical to ANDROID_STATISTICS_SCENE_FLICKER.
  • Control to select the test pattern mode. Currently identical to ANDROID_SENSOR_TEST_PATTERN_MODE.

Functions§