dichromat (version 2.0-0.1)

dalton: Effects of Daltonism (Red-Green Color Blindness)

Description

A 256-color palette as it would appear with normal vision, and with two types of red-green color blindness: protanopia and deuteronopia. Furthermore, a color palette for a type of green-blue color blindness (tritanopia) is available.

Usage

data("dalton")

Format

dalton A 256 x 3 x 4 array. The columns index the red, green and blue color values, the layers index the vision type.

dalton.colors: A list of colors, with names normal, protan, deutan, tritan.

Details

The dalton array lists a grid of 256 colors in RGB coordinates for "normal" vision as well as corresponding RGB coordinates in which certain red-green ("deutan" and "protan") or green-blue contrasts ("tritan") are collapsed.

The formulas for mapping the RGB coordinates to the collapsed coordinates have been developed in a series of papers by Brettel, Mollon, and Vi<e9>not. The protan/deutan mapping is provided in Table 2 of Vi<e9>not et al. (1999) while the tritan case is discussed in Brettel at al. (1997).

The dalton.colors list contains the sRGB colors (as R color strings) as computed with rgb from dalton.

For an automatic mapping of a given color vector to its dichromatic counterpart, see dichromat.

References

Brettel H, Vi<e9>not F, Mollon, JD (1997). Computerized Simulation of Color Appearance for Dichromats. Journal of the Optical Society of America A, 14, 2647--2655.

Vi<e9>not F, Brettel H, Ott L, M'Barek AB, Mollon JD (1995). What Do Colour-Blind People See? Nature, 376, 127--128.

Vi<e9>not F, Brettel H, Mollon JD (1999). Digital Video Colourmaps for Checking the Legibility of Displays by Dichromats. Color Research and Application, 24(4), 243--252.

See Also

dichromat, rgb

Examples

# NOT RUN {
 data("dalton", package = "dichromat")
 par(mfrow = c(4, 1))
 image(matrix(1:256, 128), col = dalton.colors$normal)
 image(matrix(1:256, 128), col = dalton.colors$deutan)
 image(matrix(1:256, 128), col = dalton.colors$protan)
 image(matrix(1:256, 128), col = dalton.colors$tritan)
# }