The Quality command computes the quality measure of a reconstructed image with respect to a source image.

The img_r and img_s parameters are the reconstructed and the source images, respectively. They must be grayscale images and have the same width, height, and order (C_order or Fortran_order).

peak = realcons

Specifies the peak value to use for the peak signal-to-noise ratio (psnr) calculation. It is ignored for the other cases. The default is 1.