Abstract
In this paper, described are color gradation techniques for rendering easily pictures and illustrations. We propose 1) color distribution curves, 2) a basic gradation technique by the interpolation method, 3) three kinds of gradation techniques based on the basic gradation technique i.e. linear, expansive and rotatable gradations, 4) a mixed gradation calculation method. These techniques are able to display gradations quickly on a graphic display, and are very useful for drawing complex gradations. A designer can draw pictures of his mental images easily using the CARP rendering system which includes these gradation techniques.
