ImageCapture doesn't care about zoomRatio on Camera

Question

I'm willing to implement zoom feature in my app with CameraX API. I followed this medium post to implement pinch to zoom and it works.

The problem is when I retrieve the captured image in onCaptureSuccess callback, The image is not zoomed.

Here is the code I use to implement zoom on Camera in onCreate():

  //ZOOM
    val listener = object : ScaleGestureDetector.SimpleOnScaleGestureListener() {
        override fun onScale(detector: ScaleGestureDetector): Boolean {
            val zoomRatio = camera?.cameraInfo?.zoomState?.value?.zoomRatio ?: 0f
            val scale = zoomRatio * detector.scaleFactor
            camera?.cameraControl?.setZoomRatio(scale)
            return true
        }
    }

    scaleDetector = ScaleGestureDetector(context, listener)

And in method "bindCameraUseCases()" :

   previewCamera.setOnTouchListener { _, event ->
            scaleDetector.onTouchEvent(event)
        }

The full method if needed :

 /** Declare and bind preview, capture and analysis use cases */
fun bindCameraUseCases() {
    // Get screen metrics used to setup camera for full screen resolution
    val metrics = DisplayMetrics().also { previewCamera.display.getRealMetrics(it) }
    Log.d(TAG, "Screen metrics: ${metrics.widthPixels} x ${metrics.heightPixels}")

    val rotation = previewCamera.display.rotation

    // Bind the CameraProvider to the LifeCycleOwner
    val cameraSelector = CameraSelector.Builder().requireLensFacing(lensFacing).build()
    val cameraProviderFuture = ProcessCameraProvider.getInstance(requireContext())
    cameraProviderFuture.addListener(Runnable {

        // CameraProvider
        val cameraProvider: ProcessCameraProvider = cameraProviderFuture.get()

        // Preview
        preview = Preview.Builder()
            .setTargetRotation(rotation)
            .build()

        previewCamera.preferredImplementationMode =
            PreviewView.ImplementationMode.TEXTURE_VIEW  // when setting to TEXTURE_VIEW, preview doesnt take full screen on back pressed

        previewCamera.setOnTouchListener { _, event ->
            scaleDetector.onTouchEvent(event)
        }

        // Default PreviewSurfaceProvider
        preview?.setSurfaceProvider(previewCamera.createSurfaceProvider(camera?.cameraInfo))


        val screenAspectRatio = aspectRatio(metrics.widthPixels, metrics.heightPixels)


        // ImageCapture
        imageCapture = ImageCapture.Builder()
            .setCaptureMode(ImageCapture.CAPTURE_MODE_MINIMIZE_LATENCY)
            .setTargetAspectRatio(screenAspectRatio)
            .setTargetRotation(rotation)
            .build()

        // ImageAnalysis
        imageAnalyzer = ImageAnalysis.Builder()
            .setTargetAspectRatio(screenAspectRatio)
            .setTargetRotation(rotation)
            .build()

        cameraProvider.unbindAll()
        try {
            camera = cameraProvider.bindToLifecycle(
                this as LifecycleOwner, cameraSelector, preview, imageCapture, imageAnalyzer
            )
        } catch (exc: Exception) {
            Log.e(TAG, "Use case binding failed", exc)
        }

    }, mainExecutor)
}

As I mentionned, zoom is working but then in onCaptureSucess, ImageProxy is not zoomed.

override fun onCaptureSuccess(image: ImageProxy) {
                        image.use { image ->
                            savedBitmap = image.imageProxyToBitmap()
                            ///...

                }
            }

Here is the extension function to retrieve bitmap from imageProxy :

fun ImageProxy.imageProxyToBitmap(): Bitmap {

val buffer = this.planes[0].buffer
buffer.rewind()
val bytes = ByteArray(buffer.capacity())
buffer.get(bytes)
val bitmap = BitmapFactory.decodeByteArray(bytes, 0, bytes.size)
val matrix = Matrix()
matrix.postRotate(90f)

return Bitmap.createBitmap(bitmap, 0, 0,bitmap.width,bitmap.height, matrix, true)

}

Here are my dependencies :

    // CameraX core library
def camerax_version = "1.0.0-beta02"
implementation "androidx.camera:camera-core:$camerax_version"

// CameraX Camera2 extensions
implementation "androidx.camera:camera-camera2:$camerax_version"

// CameraX Lifecycle library
implementation "androidx.camera:camera-lifecycle:$camerax_version"

// CameraX View class
implementation "androidx.camera:camera-view:1.0.0-alpha09"

Thank you for your help

score 0 · Answer 1 · answered Apr 10 '20 at 02:19

0

not sure why this happens but we are unable to reproduce the issue. In my test, ImageCapture always captures the image with zoom applied.

Currently I suspect this could a device issue. It could be helpful if you can provide the device name. It will also be helpful if you can verify it on other devices.

answered Apr 10 '20 at 02:19

Scott Nien

51
1

Hi @Scott. Thank you for your feedback. I have a OnePlus 5T, version 9.0.11 of Oxygen OS. I'll try to have a test on other brand. I'll let you know. Can you confirm me that code I pasted seems ok ? Thanks again for your time ! – Fanny Demey Pluvinage Apr 10 '20 at 19:03
The codes looks fine but it is not complete, so I am not sure if something wrong somewhere. By the way, how do you make sure the image is not zoomed ? Zoomed image has the same resolution as non-zoomed images and it is just the FoV (Field of View) of the image is changed. – Scott Nien Apr 12 '20 at 05:26
Thanks for mentioning Field of View, that made me realized I had to add android:adjustViewBounds="true" in my ImageView displaying the bitmap result . Sorry for the trouble and thanks again for your support. – Fanny Demey Pluvinage Apr 13 '20 at 07:52
Not a problem. Always happy to see the issue resolved. – Scott Nien Apr 14 '20 at 16:19

ImageCapture doesn't care about zoomRatio on Camera

1 Answers1