Abstract: The goal is to conquer the fault that the Euclidean distance in the traditional cylindrical coordinates cannot reasonably discriminate different colors once the color value is widely different By altering image's luminance based on its situation veracity of the color distance model is improved. The color Min edge operator can effectively detect color edges. The result shows that the new model can reasonably distinguish different colors. The color Min edge detecting operator can effectively extract color edges and suppress asymmetry illumination.