PROBLEM TO BE SOLVED: To reduce data band width necessary for access to data storage by repeating an operation for reducing a sub-structural body in each axial vector based on a bit count. SOLUTION: Chromaticity(C*) is frequently stored in a low chromaticity space so that a user can control low chromaticity value data. In node arrangement, non-linear analogy that 0, 4, 8, then 16, 24, 32, then 48, 64, then 96, 128, then 192, and then 255 is obtained. In this case, which bit in each coordinate of three data words specifies the number of times of an interpolation arithmetic operation is judged, and a bit count is set in the value of the base logarithm 2 of a difference between corresponding adjacent map node values. An operation for reducing a sub-structural body in each axial vector three-dimensionally, second-dimensionally, and one-dimensionally toward the position of a cylindrical structural body until each set bit count is turned into zero is repeated based on the bit count.
METHOD FOR INTERPOLATING THREE STIMULUS COLOR SPACE DATA