During the vector morphology processing of color image

the criterion of vector ordering is vague and one-sided. A new method of vector ordering is proposed in this paper. The gap between the visual colors is proportional to the Euclidean distance in the lab uniform color space coordinate system

and this characteristic is used to calculate the color difference

which is used as the criterion of vector ordering. The color image quaternion model and morphology structure element quaternion model are established to delimit the new morphology operators. At last

this method is used in some applications and compared with the HSV method. The experimental results show that it is better to use the proposed method to extract the image edges and reduce the salt & pepper noise.