Sensitivity of optical correlation to color change of target images

International audienceOptical correlation is based on the comparison 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 general 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 decision. The aforementioned steps can alleviate some of the problems associated with illumination changes in the target image but do utilize color information of the target image. To overcome these problems, we propose to convert the color information in contour information into a signature corresponding to the color information of the target image. This technique and test results are presented to validate its effectiveness. The preliminary results obtained with this technique are encouraging