MATLAB: How to calculate SNR of an image pixel by pixel

Question

I need to calculate SNR value in an image and show how it varies throughout the entire image. Please answer as soon as possible.

Answer 1

Try this:

snrImage = signalImage ./ noiseImage;

This requires that you know what the signal is and what the noise is. Note, you can't simply say the signal to noise ratio is the ratio of the mean of the image to the standard deviation of the image like many novices think. If you want the average SNR over all pixels, use mean():

meanSNR = mean(snrImage(:));