1. A color image processing method for detecting a contour of an object in an image, comprising the steps of: a contour position designation step wherein a position in a color image near the contour of a desired object contained in said image is designated by a user; a boundary point detection step wherein a boundary point on said contour of said object is automatically detected on the basis of designation in said contour position designation step; an object-contour tracking step wherein said contour of said object is detected by subsequently automatically detecting other points on said contour from said boundary point which has been automatically detected in said boundary point detection step; and a termination step wherein contour detection in said object-contour tracking step is checked, and said contour detection is terminated when said contour detection satisfies a prescribed condition.