How can we model types of natural scenes and the images they produce. I am especially interested in the dimensionality and scaling properties of natural images. For example, I have shown how different types of lighting conditions can be distinguished in terms of how light is distributed over the spatial positions and directions in a scene. I have also shown how well single natural images scale according to power laws. Such power laws are related to the fractal nature of images, namely that images often have similar structure at many scales.
More recent topics are motion and color.
Most motion research in the past has been concerned with the early mechanisms of how to measure image velocities at local regions of an image. Little work has been done on trying to characterize the more global types of velocities that can be produced in an image sequence. For example, how does the optical flow produced by rain or snow differ from that of a translating surface, and how can these be distinguished. Here is where dimensional and scale analyses can play a role. A second topic I am now pursuing is color.