PURPOSE: An image processing method is provided to use feature points selected from a color image and a depth image, thereby improving matching efficiency between the color image and the depth image. CONSTITUTION: The first pixel group is selected from an input color image(130). The second pixel group is selected from an input depth image. A conversion function between the first pixel group and the second pixel group is calculated based on coordinate values of each pixel(140). Each pixel of the input depth image is associated with each pixel of the input color image based on the conversion function(150).
