Three-Dimensional Control of Color Management Systems - Control of Color Imaging Systems: Analysis and Design - page 379

Corn e rs = 0 0 0 255

250

K
C
M
Y

200

150

100

50

0

0 10 20 30 40 50 60 70 80 90 100

From 0 to gamut corner

FIGURE 7.50 Example of a CMYK response to colors on neutral axis for three gamut
class GCR ( ' 0 ' on the x-axis corresponds to white (C ¼ M ¼ Y ¼ K ¼ 0)).

Corn e rs = 0 0 0 255

250

K
C
M
Y

200

150

100

50

0

0 10 20 30 40 50 60 70 80 90 100

From 0 to gamut corner

FIGURE 7.51 CMYK response to colors on neutral axis for four gamut class GCR with CMY
gamut as the fourth gamut class ( ' 0 ' on the x-axis corresponds to white (C ¼ M ¼ Y ¼ K ¼ 0)).

places, including the color management pro le LUTs. One of the key adjustments is

the selection of GCR methods. The GCR methods fine-tune the use of CMYK

separations for improving the appearance. In particular, some of the key colors
(e.g., black in flesh tones and sky tones) need less black. Sometimes, a maximum