How to set Exposure compensation in Camera X support library?

Question

I am clicking a photo using CameraX library and want to change exposure settings. What do I do to set the Exposure Compensation or change the exposure settings of picture captured?

// Set up the capture use case to allow users to take photos
val imageCaptureConfig = ImageCaptureConfig.Builder().apply {
    setLensFacing(lensFacing)
    setCaptureMode(CaptureMode.MIN_LATENCY)
    // We request aspect ratio but no resolution to match preview config but letting
    // CameraX optimize for whatever specific resolution best fits requested capture mode
    setTargetAspectRatio(screenAspectRatio)
    // Set initial target rotation, we will have to call this again if rotation changes
    // during the lifecycle of this use case
    setTargetRotation(viewFinder.display.rotation)
}.build()


imageCapture = ImageCapture(imageCaptureConfig)

// Setup image analysis pipeline that computes average pixel luminance in real time
val analyzerConfig = ImageAnalysisConfig.Builder().apply {
    setLensFacing(lensFacing)
    // Use a worker thread for image analysis to prevent preview glitches
    setCallbackHandler(Handler(analyzerThread.looper))
    // In our analysis, we care more about the latest image than analyzing *every* image
    setImageReaderMode(ImageAnalysis.ImageReaderMode.ACQUIRE_LATEST_IMAGE)
    // Set initial target rotation, we will have to call this again if rotation changes
    // during the lifecycle of this use case
    setTargetRotation(viewFinder.display.rotation)
}.build()

Answer 1

CameraX 1.0.0-beta09 has added an experimental interface for ExposureCompensation

You can set exposure by:

val camera = cameraProvider.bindToLifecycle(viewLifecycleOwner, cameraSelector, preview, imageCapture)
val cameraControl = camera.cameraControl
cameraControl.setExposureCompensationIndex(exposure)