Abstract：In calculation fractal dimension of color surface，in order to adequately consider relative information of color surface，an idea that component of RGB images—R(red)，G(green)，B(blue) is recomposed into color vector is presented. By connecting vector endpoint of different pixels to construct a coarse color surface，based on modified projective covering method，the dimension of the surface is computed，and the comparison with traditional fractal dimension of gray-scale surface is made. The result discloses that comparative to computing method of gray surface dimension，by saving R，G，B component of different pixels of RGB image in 3D matrix，the computing method of color surface dimension catches more sufficiently color information of true-color image. Thus，it can better overcome the limitation and defect——lack of consideration towards hue and saturation during the course of dimension computation of gray surface.
