User Guide

GNU Image Manipulation Program
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14.8.9.2 Description of the ‘Display Filters’ Dialog
Figure 14.51: The ‘Configure Color Display Filters’ dialog
This dialog has two small selectboxes. The left selectbox displays the Available Filters. You can move a filter to the right
selectbox by selecting it and clicking on the right arrow button. The Active Filters window on the right displays filters you
have chosen and which will be applied if the adjacent box is checked. You can move filters from the right selectbox to the left
selectbox by using the left arrow button. If you select a filter by clicking on its name, its options are displayed below the two
selectboxes, in the Configure Selected Filter area.
14.8.9.3 Color Deficient Vision
Figure 14.52: Description of the ‘Color Deficient Vision’ dialog
COLOR DEFICIENCY TYPE
Protanopia (insensitivity to red) Do not be afraid of this odd name. It is made up from three Greek roots: ‘op’ for eye, vision;
‘an’ for negation; ‘proto’ for first, the first color in the RGB Color System. So, protanopia is a visual deficiency of the
color red. It’s the well-known daltonism (red-green color blindness).
Protanopia is actually more complex than this; a person with this problem cannot see either red or green, although he is
still sensitive to yellow and blue. In addition, he has a loss of luminance perception and the hues shift toward the short
wavelengths.