Trim your face with CameraSource

Question

I am implementing the example provided by google-vision face tracker . MyFaceDetector class:

 public class MyFaceDetector extends Detector<Face> { private Detector<Face> mDelegate; MyFaceDetector(Detector<Face> delegate) { mDelegate = delegate; } public SparseArray<Face> detect(Frame frame) { return mDelegate.detect(frame); } public boolean isOperational() { return mDelegate.isOperational(); } public boolean setFocus(int id) { return mDelegate.setFocus(id); } } 

FaceTrackerActivity class:

 private void createCameraSource() { imageView = (ImageView) findViewById(R.id.face); FaceDetector faceDetector = new FaceDetector.Builder(this).build(); myFaceDetector = new MyFaceDetector(faceDetector); myFaceDetector.setProcessor(new MultiProcessor.Builder<>(new GraphicFaceTrackerFactory()) .build()); mCameraSource = new CameraSource.Builder(this, myFaceDetector) .setRequestedPreviewSize(640, 480) .setFacing(CameraSource.CAMERA_FACING_FRONT) .setRequestedFps(60.0f) .build(); if (!myFaceDetector.isOperational()) { Log.w(TAG, "Face detector dependencies are not yet available."); } } 

I need to crop my face and set it to ImageView . I can not implement my custom Frame here. frame.getBitmap() always returns null in detect(Frame frame) . How to achieve this?

Answer 1

frame.getBitmap () returns only the value if the frame was originally created from a bitmap. CameraSource supplies image information as ByteBuffers, not bitmaps, so this is available image information.

frame.getGrayscaleImageData () will return image data.

frame.getMetadata () will return metadata such as image size and image format.

Answer 2

This happens in CameraSource.java

 Frame outputFrame = new Frame.Builder() .setImageData(mPendingFrameData, mPreviewSize.getWidth(), mPreviewSize.getHeight(), ImageFormat.NV21) .setId(mPendingFrameId) .setTimestampMillis(mPendingTimeMillis) .setRotation(mRotation) .build(); int w = outputFrame.getMetadata().getWidth(); int h = outputFrame.getMetadata().getHeight(); SparseArray<Face> detectedFaces = mDetector.detect(outputFrame); Bitmap bitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888); if (detectedFaces.size() > 0) { ByteBuffer byteBufferRaw = outputFrame.getGrayscaleImageData(); byte[] byteBuffer = byteBufferRaw.array(); YuvImage yuvimage = new YuvImage(byteBuffer, ImageFormat.NV21, w, h, null); Face face = detectedFaces.valueAt(0); int left = (int) face.getPosition().x; int top = (int) face.getPosition().y; int right = (int) face.getWidth() + left; int bottom = (int) face.getHeight() + top; ByteArrayOutputStream baos = new ByteArrayOutputStream(); yuvimage.compressToJpeg(new Rect(left, top, right, bottom), 80, baos); byte[] jpegArray = baos.toByteArray(); bitmap = BitmapFactory.decodeByteArray(jpegArray, 0, jpegArray.length); } ((FaceTrackerActivity) mContext).setBitmapToImageView(bitmap);