As an example of exploratory development that's very difficult to do test-first, I've been doing a lot of image processing work lately with the objective of imp

As an example of exploratory development that's very difficult to do test-first, I've been doing a lot of image processing work lately with the objective of improving the legibility of photographs containing text. Trying to find a way to automatically test the output before putting together a solution is a unique problem unto itself, since any given set of input parameters could potentially "solve" the problem for some images but not others.