Convert CameraX Captured ImageProxy to Bitmap

Question

I was working with CameraX and had hard time converting captured ImageProxy to Bitmap. After searching and trying, I formulated a solution. Later I found that it was not optimum so I changed the design. That forced me to drop hours of work.

Since I (or someone else) might need it in a future, I decided to post here as a question and post and answer to it for reference and scrutiny. Feel free to add better answer if you have one.

The relevant code is:

class ImagePickerActivity : AppCompatActivity() {
    private var width = 325
    private var height = 205

    @RequiresApi(Build.VERSION_CODES.LOLLIPOP)
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_image_picker)

        view_finder.post { startCamera() }
    }

    @RequiresApi(Build.VERSION_CODES.LOLLIPOP)
    private fun startCamera() {
        // Create configuration object for the viewfinder use case
        val previewConfig = PreviewConfig.Builder().apply {
            setTargetAspectRatio(Rational(1, 1))
            //setTargetResolution(Size(width, height))
            setLensFacing(CameraX.LensFacing.BACK)
            setTargetAspectRatio(Rational(width, height))
        }.build()

        }

        // Create configuration object for the image capture use case
        val imageCaptureConfig = ImageCaptureConfig.Builder()
            .apply {
                setTargetAspectRatio(Rational(1, 1))
                // We don't set a resolution for image capture instead, we
                // select a capture mode which will infer the appropriate
                // resolution based on aspect ration and requested mode
                setCaptureMode(ImageCapture.CaptureMode.MIN_LATENCY)
            }.build()

        // Build the image capture use case and attach button click listener
        val imageCapture = ImageCapture(imageCaptureConfig)
        capture_button.setOnClickListener {

            imageCapture.takePicture(object : ImageCapture.OnImageCapturedListener() {
                override fun onCaptureSuccess(image: ImageProxy?, rotationDegrees: Int) {
                        //How do I get the bitmap here?
                        //imageView.setImageBitmap(someBitmap)
                }

                override fun onError(useCaseError: ImageCapture.UseCaseError?, message: String?, cause: Throwable?) {
                    val msg = "Photo capture failed: $message"
                    Toast.makeText(baseContext, msg, Toast.LENGTH_SHORT).show()
                    Log.e(localClassName, msg)
                    cause?.printStackTrace()
                }
            })
        }
        CameraX.bindToLifecycle(this, preview, imageCapture)
    }

}

score 11 · Accepted Answer · answered Aug 09 '19 at 14:52

So the solution was to add extension method to Image and here is the code

class ImagePickerActivity : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_image_picker)
    }

    private fun startCamera() {

        val imageCapture = ImageCapture(imageCaptureConfig)
        capture_button.setOnClickListener {

            imageCapture.takePicture(object : ImageCapture.OnImageCapturedListener() {
                override fun onCaptureSuccess(image: ImageProxy?, rotationDegrees: Int) {
                    imageView.setImageBitmap(image.image?.toBitmap())
                }
                //.....
            })
        }
    }

}

fun Image.toBitmap(): Bitmap {
    val buffer = planes[0].buffer
    buffer.rewind()
    val bytes = ByteArray(buffer.capacity())
    buffer.get(bytes)
    return BitmapFactory.decodeByteArray(bytes, 0, bytes.size)
}

score 8 · Answer 2 · answered Aug 09 '19 at 15:18

Slightly modified version. Using the inline function use on the Closable ImageProxy

imageCapture.takePicture(
           object : ImageCapture.OnImageCapturedListener() {
               override fun onCaptureSuccess(image: ImageProxy?, rotationDegrees: Int) {
                     image.use { image ->
                           val bitmap: Bitmap? = image?.let {
                                imageProxyToBitmap(it)
                            } ?: return
                      }
          }
       })

  private fun imageProxyToBitmap(image: ImageProxy): Bitmap {
        val buffer: ByteBuffer = image.planes[0].buffer
        val bytes = ByteArray(buffer.remaining())
        buffer.get(bytes)
        return BitmapFactory.decodeByteArray(bytes, 0, bytes.size)
    }

@Bender `super.onCaptureSuccess` it closes the image, so check it is not called before getting the image buffer. — marc.garcia, Mar 06 '20 at 10:14
@Blackbelt one year later and still there is no other way out, or am I missing something? — Sarthak Mittal, Aug 16 '20 at 20:12

Peppy Appz · Answer 3 · 2021-09-12T15:47:28.503

8

Here is the safest approach, using MLKit's own implementation. Tested and working on MLKit version 1.0.1

import com.google.mlkit.vision.common.internal.ImageConvertUtils;

Image mediaImage = imageProxy.getImage();
InputImage image = InputImage.fromMediaImage(mediaImage, imageProxy.getImageInfo().getRotationDegrees());
Bitmap bitmap = ImageConvertUtils.getInstance().getUpRightBitmap(image)

edited Sep 12 '21 at 15:47

answered Sep 12 '21 at 06:25

Peppy Appz

89
1
2

score 6 · Answer 4 · answered Jun 05 '20 at 02:50

Java Implementation of Backbelt's Answer.

private Bitmap imageProxyToBitmap(ImageProxy image) {
    ByteBuffer buffer = image.getPlanes()[0].getBuffer();
    byte[] bytes = new byte[buffer.remaining()];
    buffer.get(bytes);
    return BitmapFactory.decodeByteArray(bytes,0,bytes.length,null);
}

score 0 · Answer 5 · answered May 30 '20 at 17:26

There is second version of takePicture method at the moment (CameraX version 1.0.0-beta03). It provides several ways to persist image (OutputStream or maybe File can be useful in your case).

If you still want to convert ImageProxy to Bitmap here is my answer to similar question, which gives the correct implemetation of this conversion.

score -1 · Answer 6 · answered Nov 30 '21 at 17:33

-1

Please kindly take a look at this answer. All you need to apply it to your question is to get Image out of your ImageProxy

Image img = imaget.getImage();

answered Nov 30 '21 at 17:33

basileus

295
3
9

Convert CameraX Captured ImageProxy to Bitmap

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