We propose pattern location algorithms for multichannel images. Colored ima
ges are taken as example for simulations and experimental results. We consi
der the model of a target with different luminance in each channel, and Gau
ssian additive noise, independent and with different noise levels in each c
hannel. The maximum likelihood (ML) estimation of the location of the targe
t in a given scene leads to optimal combination of the multichannel informa
tion. We develop algorithms to obtain the target location when the target l
uminance and the variance of the noise are either known or unknown in each
channel. The proposed algorithms have a total complexity of a correlation.
A comparison with the results obtained by classical addition of correlation
s values calculated in each channel is made, demonstrating the superiority
of the optimal algorithms. Simulations are developed to test the robustness
of the proposed algorithms when the hypothesis of Gaussian and white noise
are not fulfilled. The results show that the performance of the estimation
do not reduce for exponential white noise or uniform white noise, but the
performance deteriorates when the noise is correlated. (C) 1999 Elsevier Sc
ience B.V. All rights reserved.