Random pattern generator?

I am currently developing an app that will need to recognize and distinguish different patterns, and I currently need 54 unique, easily distinguishable patterns that are not too intricate for a normal mobile camera to read. The patterns can use any means possible to distinguish themselves, but I would like for each pattern to follow the same style. The goal is for the app to distinguish each pattern without it being too easy to distinguish them with the naked eye. I have considered using a simple 3x3 or 2x2 square sporting 4-9 different coloured squares for each pattern, but I've also seen images where there is a mash of colours with waves going through, used for similar puproses, but I am afraid this pattern will be too difficult for the app to distinguish between. Especially if there are 54 of them. Is there any application that I can use to generate these patterns while guaranteeing that no two patterns look too much alike? The best I've found so far is a knitting-pattern generator, but that makes a random sheet of pattern with no regards for uniqueness.

I hope I'm not asking for too much, but I can't seem to find a good algorithm to work this out anywhere. If no such program exists I will have to make these patterns myself, but I would like to avoid that at any cost, as it's likely to cause a lot of similar patterns.

Thank you all in advance.