Opponent color processing
= Opponent color processing
{title2=$g_LQ_L-g_MQ_M$}
A class of post-receptoral computations comparing signals from different cone populations, for example a gain-weighted L–M difference and an S versus L+M comparison. Such comparisons distinguish spectral differences from shared changes in illumination <intensity>. Receptor counts, signal gains and later appearance judgments need not vary proportionally.