Monday, September 12, 2005

Vision is not inverse optics

While thinking about the microstructure of rough materials and microfacet lighting models such as the Torrence-Sparrow or Oren-Nayar models, I came to the hypothetical epiphany that vision is not inverse optics.

I should clarify. There are two types of vision, namely computational human vision and computational extraterrestrial vision. Computational human vision is concerned with high level vision tasks such as object detection, object learning/discovery, and overall scene understanding. Computational extraterrestrial vision is concerned with understanding how light interacts with matter and how we can infer low level properties of substances given their images. We should look at this computational extraterrestrial vision goal as something that would help scientists see things that the naked eye cannot see. However, I vehemently protest the idea that we need anything like a Oren-Nayar lighting model to be able to do object detection in the way humans can do it.

When I was younger (4 years ago) I wanted to be a theoretical physicist. Back then I envisioned that in graduate school I would be writing simulations of quantum chromodynamics. I thought that by starting with small things (gluons, quarks, photons, electrons) I could one day help put together all of the pieces scientists have been collecting over the years. However, I have abandoned this goal of understanding the world via physics. I have little faith in the bottom-up approach to modeling reality.

I believe that by studying computational human vision, I am following the Top-Down approach to modeling reality. For a long time I've had this vision of a new quantum mechanics, a new physics where the indivisble units are 'cats' and 'trees' and 'cars,' namely the indivisible units of human experience.