Android Camera - How can i take a specific “rectangle” from the byte array?

Question

I have created an application that shoots and saves photos. I have a preview and an overlay on top of that preview. The overlay defines a square (the area around the square

Answer 1

The camera preview data comes in YUV format (specifically ImageFormat.NV21), which BitmapFactory doesn't support directly. You can use YuvImage to convert it to a Bitmap as described here. The only difference is that you'll want to pass a Rect corresponding to the square that you want when calling YuvImage.compressToJpeg.

Answer 2

It took me some time to figure out that the code should look like this:

int[] pixels = new int[100*100];//the size of the array is the dimensions of the sub-photo
        ByteArrayOutputStream bos = new ByteArrayOutputStream();
        Bitmap bitmap = BitmapFactory.decodeByteArray(data , 0, data.length);
        bitmap.getPixels(pixels, 0, 100, 350, 50, 100, 100);//the stride value is (in my case) the width value
        bitmap = Bitmap.createBitmap(pixels, 0, 100, 100, 100, Config.ARGB_8888);//ARGB_8888 is a good quality configuration
        bitmap.compress(CompressFormat.JPEG, 100, bos);//100 is the best quality possibe
        byte[] square = bos.toByteArray();