1. A machine vision method comprising: sensing light energy associated with a scene; generating color image data representing at least a portion of the scene, wherein the data are arranged as pixels, and the data for a given pixel comprise an intensity value, a hue value, and a chroma value, the intensity value representing the total sensed light energy associated with the pixel, the hue value representing a dominant or average frequency of the light energy associated with the pixel, and the chroma value representing a measure of the light energy on a side of the visible spectrum complementary to the hue.