Patent ID: 7599552

Claim:
A color conversion method of inputting first and second color difference values and obtaining a corresponding saturation value, comprising steps of: creating a main lookup table which stores saturation values for color difference values, and a sub-lookup table for obtaining a value corresponding to the first color difference value for accessing the main lookup table, wherein the first color difference value is equal to or less than the second color difference value; accessing the sub-lookup table with the first color difference value to obtain the value corresponding to the first color difference value; determining an address of the main lookup table in correspondence with the first and second color difference values on the basis of the value obtained in the accessing step and a difference between the first and second color difference values; and obtaining a saturation value corresponding to the first and second color difference values by accessing the main lookup table with the address determined in the determining step, wherein the main lookup table has a smaller number of entries than the number of all possible combinations of the first and second color difference values by utilizing symmetry of the saturation value for the first and second color difference values.