Detecting human faces in color images

A method for detecting human faces in color images is described that first separates skin regions from nonskin regions and then locates faces within skin regions. A chroma chart is prepared via a training process that contains the likelihoods of different colors representing the skin. Using the chroma chart, a color image is transformed into a gray scale image in such a way that the gray value at a pixel shows the likelihood of the pixel representing the skin. An obtained gray scale image is then segmented to skin and nonskin regions, and model faces representing front- and side-view faces are used in a template-matching process to detect faces within skin regions. The false-positive and false-negative errors of the proposed face-detection method on color images of size 300×220 and containing four or fewer faces are 0.04 or less.