imagesnr.m

jpg compression and decompression~

function snr=imageSNR(origImage, newImage)
%
% imageSNR - returns the SNR of a newImage given an original image
% which the newImage is replicating. origImage is the name of a tiff
% image which is losslessly compressed, and newImage the name of a JPG
% file which is lossy
%
[rOrig gOrig bOrig]=tiffread(origImage);
original=[rOrig gOrig bOrig];

[rComp gComp bComp]=jpgread(newImage);
comp=[rComp gComp bComp];

snr=10*log10(sum(sum(origImage .^2))/sum(sum((original-comp).^2)));