Three-Dimensional Control of Color Management Systems - Control of Color Imaging Systems: Analysis and Design - page 400

FIGURE 7.64 (See color insert following page 428.) (a) (left) and (b) (right): Gamut
views from top and from bottom, respectively; (c) lines to gamut corners (cyan, magenta,
yellow, white, and blue corners from 100,0,0 point); (d) lines to gamut corners (cyan,
magenta, yellow, white, and blue corners from 50,0,0 point).

show the CMYK response (left) and round trip accuracy (right) when a line stimulus
is used from L*

¼ 100, a* ¼ b* ¼ 0 point to 14 different gamut corners. Similar plots

are shown from L* ¼ 50, a* ¼ b* ¼ 0 in Figure 7.65(e-i). - i). The x-axis contains

101 discrete points along the line between the starting point (L* 0)

to the corner. The corner is shown with a thick vertical line in each of these plots.
The x-axis, representing the points on the gamut corner axis, is extended until it
touches the sides of the L*a*b* cube. The corner point shown is always at 100.
The space between 0 and 100 units is the in-gamut axis and the space between the
red vertical lines (at 100) to the end is the out-of-gamut region. The line can be
expressed in L*a*b* space by the line equation with a start point {L 0 a 0 b 0 } and

¼ 50, a* ¼ b* ¼