How to find image quality using cnr?

How to find image quality using cnr?

[Walter Roberson]

CNR appears to be Contrast to Noise Ratio

Answer 1

[Walter Roberson]

https://www.mathworks.com/matlabcentral/fileexchange/33529-a-new-visibility-metric-for-haze-images

[Selva Karna]

actually my request question is how to check image quality without reference image , so?

[Walter Roberson]

(Some definitions for calculating CNR are given at http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0077089 )

[Walter Roberson]

SNR and CNR are always defined as a measure of the difference between a noisy signal and a reference less-noisy signal. If you only have one image, then the only way you can calculate SNR or CNR is if you have distinct regions where part is noisy and part is less so, and you measure within the respective ROIs and calculate based on those.

Answer 2

[r r]

I have an image that contains a tumor and I want to calculate the rate of contrast for this tumor within the image , please help me