How to save bitmap from GLSurfaceView (Only bitmap, not whole texture)

Question

I am using this code to give multiple effect on bitmap that is on GlSurfaceView. apply-effects-on-image-using-effects

Now, I want to save the bitmap. They have given

Answer 1

If you can get the dimensions of the image, you can get the exact position of the bitmap.

Let the image dimensions be x and y, and get the screen dimensions following this post. Let that be a and b.

Your starting position will be ((a-x)/2, (b-y)/2).

Use this to crop your image.