My first image is my ok master image and second image is my current image how can i know the difference between them and how can i check my image is blurry or noisy.

[Walter Roberson]

See https://www.mathworks.com/help/images/ref/imshowpair.html

[Shri.s]

i want to show this blurry image as NG it will work by imshowpair command but i want to know how can we define is this image is blurry or not ?

[Walter Roberson]

Spread some grey grey glitter on a larger black surface. Using a high quality camera, pull the camera away until the point where the pixel resolution is larger than an individual piece of glitter. Take a picture.

Now, given only that one picture, how can you tell whether the picture is a good quality picture of glitter, the best you could hope for at that resolution and that distance (next to no noise) — or if instead you have a noisy picture of a black background?

[Walter Roberson]

This is actually a serious problem in science.

In the earlier days of astronomical images they found that some of the images were fuzzy. They thought that they had built the devices incorrectly so they built the devices more carefully and to higher resolution, trying to get rid of what they thought must be some unknown systematic error in construction, but the better they did, the more fuzziness was discovered.

What they had discovered was Cosmic Microwave Background Radiation. It is "noise" relative to the images they wanted at the time, but it turns out to be a signal itself that has a lot of information hidden in it.

There is no way to determine whether you have a noisy image or if instead you have a good quality image that contains a signal that you were not expecting. Any source of noise is potentially a signal.