SurfaceView中的特定区域

Question

我需要一点帮助。我添加了Google Vision API以检测图像中的文本，为此，图像来自相机，因此它是动态的。相机放置在SurfaceView上，并捕获在surfaceView上找到的文本。我需要SurfaceView可以捕获整个图像的功能，但是文本仅取自我定义的特定区域。简而言之，“在摄像机中添加限制（如矩形），以便图像处理的数据/文本仅来自该矩形”

mCameraSource = new CameraSource.Builder(this, textRecognizer)
        .setFacing(CameraSource.CAMERA_FACING_BACK)
        .setRequestedPreviewSize(1280, 1024)
        .setAutoFocusEnabled(true)
        .setRequestedFps(2.0f)
        .build();

mSurfaceView.getHolder().addCallback(new SurfaceHolder.Callback() {
    @Override
    public void surfaceCreated(SurfaceHolder holder) {
        try {
            if (ActivityCompat.checkSelfPermission(RechargeActivity.this, Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED) {

                ActivityCompat.requestPermissions(RechargeActivity.this,
                        new String[]{Manifest.permission.CAMERA},
                        RequestCameraPermissionID);
                return;
            }
            mCameraSource.start(mSurfaceView.getHolder());
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    @Override
    public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {

    }

    @Override
    public void surfaceDestroyed(SurfaceHolder holder) {
        mCameraSource.stop();
    }
});