function mse = mserror(A, B)

% The function takes two equal images and calculates the mean square 
% difference inbetween the two.
% Usage: 	MSE = MSERROR(A, B, NSIZE);
% where		A: 	first image
%		B:	second image
%		NSIZE:	size of the images


	diff = A - B;			% difference
	diff_sq = diff .^ 2;		% difference squared
	mse_clmn = mean(diff_sq);	% means square diff. of the columns;
	mse = mean(mse_clmn);