*"*If there is a difference, it sould be obvious as the images altinate."

Same result I got cropping into 2 images and flipping back and forth. Tried overlaying, compositing half of one onto the other - no visible difference I can detect but I have bad eyes. I wonder if you flip them horizontally, does the 'better' one always end up on the right? Any differences would seem to be so small that it might take a randomized double blind test over several images to try to tease them out. * *

"Democracy is a pathetic belief in the collective wisdom of individual ignorance." - H. L. Mencken