local image transformations

Fergus came by in the morning to discuss modeling speckles as a function of wavelength in coronography, and we spent a while counting parameters. As is usual in these discussions I have with vision people, there are more parameters than data points in the natural models we want to write down. So we either have to apply priors, or else simplify the model; we decided to do the latter. The odd thing (in my mind) is that simplifying the model (that is, reducing the number of free parameters) is actually equivalent to applying extremely strong priors. So the idea that one can "avoid using priors" by choosing a simpler model is straight-up wrong, no? That said, I am very happy with Fergus's beautiful model, which involves an extremely general description of how one might transform an image locally.