What does negative value of PSNR indicate?
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I am computing the PSNR value between an image and its filtered version and getting a negative value.
I understand tht since there is log, if the number is less than 1, I will be getting a negative value.
But what does the negative value actually imply??
Raunak Gupta on 14 Nov 2020
According to the definition of PSNR as mentioned here , it cannot be negative. You can check if the range in both images is same as in if both images are of datatype unit8 then range should be [0,255]. Also, if you are converting one image to be in range [0,1] and the other image is in range [0,255] then this behavior can occur. Finally, if you are using your own implementation for psnr then I would suggest using built-in function psnr for calculating the same.
The only reason I can think of is a big mismatch between the range of values in the image.
Hope this helps!
More Answers (1)
Walter Roberson on 14 Nov 2020
-- you can get negative PSNR if your signal is less than your noise.