A channel transformation based on opponent-color theory of the color v
ision models is applied to optical pattern recognition so that the con
ventional red, green, and blue (RGB) channels are transformed into bri
ght-dark, red-green, and yellow-blue (ATD) channels. Matched filtering
and correlation are performed over the new components of the target a
nd the scene in the ATD system. The proposed transformation allows us
to reduce the number of channels commonly used in color pattern recogn
ition, passing from the three RGB channels to the two red-green and ye
llow-blue opponent-color channels. (C) 1995 Optical Society of America