I have some old wallpaper samples/scans (think wall covering, not something from Photoshop or Illustrator). The patterns have a repeat but the samples do not isolate the repeat. Does anyone know if there is a software tool or general technique for finding the repeat and extracting it from a larger sample other than eyeballing it, cropping and seeing if you have lucked into finding the exact pixel to trim the image on? I've found lots of tutorials on creating repeating patterns from scratch but haven't been able to find the right combination of words to get Bing or Google to give me what I'm looking for.