It is not clearly mentioned as to consider the peak value or the range in most internet sources. In my case peak becomes 1 and range is 2. What should I go with?
Im not expert at this field, but what about change image [-1, 1] -> [0, 2] and there will be no problem:D
More seriously, PSNR formula is 10log(MAX^2 / MSE). So in standard case PSNR = 0 if MAX = 255 and MSE =255^2 then log(1) = 0. Analogously, your maximal MSE can be 4 (one pixel is 1, in the next image -1). The max should be 2. then 2^2/4 = 1 is hold.
Result is: for image from range [-1, 1], the max in psnr formula has to be 2.
In my opinion, I hope im right.
In my opinion PSNR uses the maximum power that the signal can reach. In your case, as the pixel values ranges between -1 to 1, the maximum power is 22. The expression for PSNR is 10*log10(22/sigma2), where sigma stands for the standard deviation of noise.
I hope it helps
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