Image Formation

Low-level vision converts a scene to a 2D image. For example, consider a pinhole camera:

This camera inverts the image. It provides a perspective projection. - parallel-line vanishing point - scaled orthographic projection - assume objects of negligible depth - perspective approximated as scaling

The lens system of this system is a camera with 512x512 pixels resolution, which is 256K pixels. By comparison, the human eye has 120M rods.

- photometry - light reflected either - diffusely: absorbed and then emitted in all directions - specularly: reflected off surface in a particular direction - spectrophotometry - image intensity I(x,y,t) at location (x,y) at time t - multidimensional based on different light wavelengths - typically assume three-dimensional for red-green-blue colors