Polarity Matching Principle

The polarity matching principle is a constraint that can be used to solve the motion correspondence problem.  According to this constraint, motion correspondence matches are assigned between elements of identical contrast (e.g. between two elements that are both light against a dark background, or between two elements that are both dark against a light background) (Dawson et al., 1994).  It is a natural constraint because movement of an object in the world might change its shape and color, but are unlikely to alter its contrast relative to its background.

References:

1. Dawson, M. R. W., Nevin-Meadows, N., & Wright, R. D. (1994). Polarity matching in the Ternus configuration. Vision Research, 34, 3347-3359.

(Added March 2011)