This invention has as its object to provide a color separation table generation
method which can improve grayscale characteristics and can suppress generation
of a pseudo edge of a reproduced image by introducing a nonlinear interpolation
method using a finite element method. To this end, according to the present invention,
a color separation table generation method of generating a color separation table
used to separate an input color into a plurality of color agent colors, includes:
a first table generation step of generating color separation data on a first line
that connects white and black points in the color separation table; a second table
generation step of generating color separation data on a plurality of second lines
each of which connects the white point and each of primary color points each expressed
by one of the color agent colors and secondary color points each expressed by two
of the color agent colors; a third table generation step of generating color separation
data on a plurality of third lines each of which connects each of the primary and
secondary color points and the black point; a fourth table generation step of generating
color separation data on a plurality of fourth lines each of which connects the
primary and secondary color points; and an interpolation step of generating color
separation data at grid points inside a three-dimensional color space by an interpolation
process based on the color separation data on the first to fourth lines, wherein
the interpolation step includes a step of executing an interpolation process using
a finite element method for each triangular plane specified on the color space.
