function SECBIGGER = framedifference (SECTIONS) ssize = size(SECTIONS); for ii = ssize(1):-1:2 FREQDIFF(ii-1,:) = SECTIONS(ii-1,:)-SECTIONS(ii,:); end for jj = 2:ssize(2) SECDIFF(:,jj-1) = FREQDIFF(:,jj) - FREQDIFF(:,jj-1); end for ii = 1:ssize(1)-1 for jj = 1:ssize(2)-1 if SECDIFF(ii,jj) > 0 SECBIGGER(ii,jj) = 1; end end end