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

dalton {dichromat} | R Documentation

## 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 Viénot. The protan/deutan mapping is provided in Table 2 of Viénot 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`.

### Source

The data were kindly provided by Françoise Viénot.

The deutan/protan data (rounded to integers) is also available in Table 2 of Viénot et al. (1999). See also http://tsi.enst.fr/~brettel/CRA24/table2.html.

### References

Brettel H, Viénot F, Mollon, JD (1997). Computerized Simulation of Color Appearance for Dichromats. Journal of the Optical Society of America A, 14, 2647–2655.

Viénot F, Brettel H, Ott L, M'Barek AB, Mollon JD (1995). What Do Colour-Blind People See? Nature, 376, 127–128.

Viénot 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

     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)

[Package dichromat version 2.0-0 Index]