Normal trichromat
Deuteranope
Tritanope
Protanope
Normal trichromat |
Deuteranope |
Tritanope |
Protanope |
Figure 1.14 from Sharpe, L. T., Stockman, A., Jägle, H., & Nathans, J. (1999). Opsin genes, cone photopigments, color vision and colorblindness. In K. Gegenfurtner & L. T. Sharpe (Eds.), Color vision: From Genes to Perception (pp. 3-51) Cambridge: Cambridge University Press.
Simulations of the perceptual experiences of different types of colour-deficient dichromatic observers. Four different images of a scene from a fruit stall are shown as they might be perceived by a normal trichromat (top left), a deuteranope (top right), a protanope (bottom right), and a tritanope (bottom left). The simulations are based on an algorithm incorporating a colorimetric transformation, which also makes explicit assumptions about the residual sensations experienced by dichromats (see Viénot et al., 1995; Brettel et al., 1997). The transformation replaces the value of each original element by thecorresponding value projected onto a reduced color stimulus surface, parallel to the direction of the missing cone fundamental axis in an LMS cone excitation space. It is informed by assumptions about the neutral zones of dichromats and the colors perceived by unilateral colorblind observers. The simulations must be treated as approximate, not only because of the limitations of the strictly colorimetric transformation involved and of the printing procedure, but also because the transformed image is viewed by the normal visual system, which will process it differently than the colour blind system.
Brettel, H., Viénot, F., & Mollon, J. D. (1997). Computerized simulation of color appearance for dichromats. Journal of the Optical Society of America A, 14, 2647-2655.
Sharpe, L. T., Stockman, A., Jägle, H., & Nathans, J. (1999). Opsin genes, cone photopigments, color vision and colorblindness. In K. Gegenfurtner & L. T. Sharpe (Eds.), Color vision: From Genes to Perception (pp. 3-51) Cambridge: Cambridge University Press.
Viénot, F., Brettel, H., Ott, L., Ben, M. B. A., & Mollon, J. D. (1995). What do colour-blind people see? Nature, 376(6536), 127-128.