My personal favorite for identifying patterns is a neural network. Doing a google search for Neural Network Pattern Recognition would yield much information on the subject. That said, ANN trading isn't new, and since it isn't the defacto standard for beating the markets, it isn't really that reliable. On the other hand, real neural networks can make some of the best traders out there - which means that the network just needs to be constructed correctly.
That said, consider this. Trading software evolves. The market makers, the home ATM trades, all of it. A strategy that works now may not work tomorrow, or yesterday (or next year / the year before, time scale is moot)
The point I'm getting at is the micro-patterns you'd be looking for are burried in a huge mass of macro-patterns. You'd need to be able to identify trades by origin, to identify their patterns. Looking at "the market", all you can do is pattern the market. And since the market evolves, by the time you isolate the pattern, it is different than it was.
