I am using following method to taking screen shot of a particular view which is a SurfaceView.
public void takeScreenShot(View surface_view){
// create
Once you get the bitmap, you can copy only a part of it like this:
private Bitmap copyBitmap(Bitmap src){
//Copy the whole bitmap
//Bitmap newBitmap = Bitmap.createBitmap(src);
//Copy the center part only
int w = src.getWidth();
int h = src.getHeight();
Bitmap newBitmap = Bitmap.createBitmap(src, w/4, h/4, w/2, h/2);
return newBitmap;
}