I am trying to do image stitching of two images that have been shifted vertically and don't really contain a whole lot of features. Harris doesn't find anything, the blob detector finds random spots... I also tried PSNR and SSIM without success (the results are always very similar).
The images are pictures of walls. I can see where they should match by eye, so there is some detail in the pictures (grain and so on, different tones of the same color, etc).
How would you do it?