Patent ID: 7307753

Claim:
A color processing method for generating an output color signal containing a black colorant in an output color space from an object color signal in an object color space and an input black colorant quantity associated with the object color signal, the color processing method comprising: calculating an equivalent output black colorant quantity in the output color space from the input black colorant quantity, the equivalent output black colorant quantity being equivalent to the input black colorant quantity; determining if a first color signal in the output color space satisfies a coverage restriction, the first color signal being calculated from the object color signal and the equivalent output black colorant quantity; calculating an optimum black colorant quantity so that a second color signal in the output color space satisfies the coverage restriction if the first color signal does not satisfy the coverage restriction, the second color signal being calculated based on the obiect color signal and the equivalent output black colorant quantity and has the optimum black colorant quantity, the optimum black colorant quantity being calculated based on the equivalent black colorant quantity and a minimum black colorant quantity of the object color signal satisfying the coverage restriction; and calculating an optimum color signal corresponding to the optimum black colorant quantity.