  One of the problems of conventional visual quality evaluation criteria such
as PSNR and MSE is the lack of appropriate standards based on the human visual
system (HVS). They are calculated based on the difference of the corresponding
pixels in the original and manipulated image. Hence, they practically do not
provide a correct understanding of the image quality. Watermarking is an image
processing application in which the image's visual quality is an essential
criterion for its evaluation. Watermarking requires a criterion based on the
HVS that provides more accurate values than conventional measures such as PSNR.
This paper proposes a weighted fuzzy-based criterion that tries to find
essential parts of an image based on the HVS. Then these parts will have larger
weights in computing the final value of PSNR. We compare our results against
standard PSNR, and our experiments show considerable consequences.
