Sensitivity of optical correlation to color change of target images

Correlation is based pattern recognition is primarily based on the matching of contours between an unknown target image and a known reference image. However, it does not usually include the color image information in the decision making process. In order to render the correlation method sensitive to color change, we propose a generalized method based on the decomposition of the target image in its three color components using, either the normalized RGB (red, green, blue) color space, or the normalized HSV (hue, saturation, value) space. Then, the correlation operation is carried out for each color component and the results are merged in order to make a final decision. The aforementioned steps can alleviate majority of the problems associated with illumination changes in the target image by utilizing color information of the target image. To overcome these problems, we propose to convert the color based contour information into a signature corresponding to the color information of the target image. Test results are presented to validate the effectiveness of the proposed technique.