How can I check photograph quality? [duplicate]

This question already has answers here: Closed 12 years ago.

Possible Duplicate:

How can I check out the picture quality in program using c#?

Can I check whether noise is add开发者_运维百科ed to a photograph using c#?

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Basically, to detect noise what I think you are going to want to do is find pixels that are discontinuous (in color or brightness) from other pixels.

In any given photograph, a valid pixel is highly likely to be correlated (similar) in color or intensity to one or more pixels around it. Noise is not the same (or similar) color as any other pixel around it; it is discontinuous from all surrounding pixels.

If a pixel is similar or identical in color to surrounding pixels, it is probably not noise, and it's not going to look like noise; it's going to look like part of the picture..