There is definitely room for better and less gameable quality evaluation functions than PSNR and SSIM, but I would have liked to see at a minimum a description of how the algorithm was designed and a practical evaluation against other similarity metrics.<p>See e.g. the graphs in <a href="https:&#x2F;&#x2F;ece.uwaterloo.ca&#x2F;~z70wang&#x2F;research&#x2F;ssimplus&#x2F;" rel="nofollow">https:&#x2F;&#x2F;ece.uwaterloo.ca&#x2F;~z70wang&#x2F;research&#x2F;ssimplus&#x2F;</a> comparing human assigned scores against different similarity metrics.