Tutorial3-Camera Control: picture freezed after takePicture()

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[Update: Please see my update answer below this text]

When a picture is taken with the "OpenCV Tutorial3 - Camera Control" app the taken picture is freezed on the screen and the preview doesn't come back. I tested it with Smartphone Android 2.2.2 and Tablet Android 3.2.1 device: Both the same.

The relevant code:

Tutorial3Activity.java:

@SuppressLint("SimpleDateFormat")
@Override
public boolean onTouch(View v, MotionEvent event) {
    Log.i(TAG,"onTouch event");
    SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd_HH-mm-ss");
    String currentDateandTime = sdf.format(new Date());
    String fileName = Environment.getExternalStorageDirectory().getPath() +
                           "/sample_picture_" + currentDateandTime + ".jpg";
    mOpenCvCameraView.takePicture(fileName);
    Toast.makeText(this, fileName + " saved", Toast.LENGTH_SHORT).show();
    return false;
}

Tutorial3View.java:

public void takePicture(final String fileName) {
    Log.i(TAG, "Tacking picture");
    PictureCallback callback = new PictureCallback() {

        private String mPictureFileName = fileName;

        @Override
        public void onPictureTaken(byte[] data, Camera camera) {
            Log.i(TAG, "Saving a bitmap to file");
            Bitmap picture = BitmapFactory.decodeByteArray(data, 0, data.length);
            try {
                FileOutputStream out = new FileOutputStream(mPictureFileName);
                picture.compress(Bitmap.CompressFormat.JPEG, 90, out);
                picture.recycle();
                mCamera.startPreview();
            } catch (Exception e) {
                e.printStackTrace();
            }
            return;
        }
    };

    mCamera.takePicture(null, null, callback);
}

What can I do to come back to the preview screen after taken a picture?

There is a mCamera.startPreview() command in the takePicture method but it seems not to have the effect to set the preview screen.