Color-invariant character recognition and character-background color identification by multichannel matched filter

The problem to recognizing a uniform color object placed on a color background is studied. The recognition process, based on a multichannel correlation, is divided into two steps. First, the presence of the target is determined by using two phase only filters (POF) in each channel matched to the target on a black background, and to a color square with the target in black. The background color is obtained with a classical matched filter (CMF) matched to the latter signal. From the information provided by the three filters in each channel, it is possible to obtain the presence of the target and the character-background color combination. Some simulation results are given to show the performance of the method.