Dichromacy (java & class files) This plugin for ImageJ/Fiji simulates the three main types dichromatic vision (or colour blindness) due to lack of function or absence of retinal photosensitive pigments: protanopia (red), deuteranopia (green) and tritanopia (blue cones deficiency).
There are other milder colour vision deficiencies due to altered or shifted spectral responses of the photoreceptors. These are called protanomaly, deuteranomaly and tritanomaly respectively. Complete monochromatic vision is called achromatopsia.

The plugin source code is based on the C++ version of Scribus module colorblind.cpp (licensed as GPL).
The Scribus code was, in turn, based on Gimp's display filter for colour blind simulation (also licensed as GPL) which implements the algorithm described in Reference [2] below (see http://vischeck.com/ for more info). Unfortunately both Scribus and GIMP colour transformations contained a bug in the gamma processing that simulates the values of RGB pixels when displayed on a device of gamma ~ 2.0. Robert Dougherty and Alex Wade, (authors of the Vischeck plugin) kindly suggested the fix of the gamma bug. Their help in the implementation is therefore greately appreciated.

The advantage of Dichromacy over the Vischeck plugin is that it can be recorded and called from scripts and macros, without user interaction.


Dichromatic simulation

A: Normal trichromatic view, B: protanope simulation, C: deuteranope simulation, D: tritanope simulation.

We have developed two methods to enhance Haematoxylin and Eosin stained histological sections. The details of these methods can be found in reference 4, below.


  1. Viénot F, Brettel H, Ott L, Ben M'Barek A, Mollon JD. What do colour-blind people see? Nature 376, pp.127-128, 1995. ( PDF)
  2. Brettel H, Viénot F, Mollon JD, Computerized simulation of color appearance for dichromats, J. Opt. Soc. Am. A 14, 2647-2655 (1997). (PDF)
  3. Viénot F, Brettel H, Mollon JD. Digital video colourmaps for checking the legibility of displays by dichromats. Color Res. Appl. 24(4), pp. 243-252, 1999.
  4. Landini G, Perryer DG. Digital enhancement of haematoxylin and eosin-stained histological images for red–green colour-blind observers. Journal of Microscopy 234 (3) 293-301, 2009. (PDF)
  5. Landini G, Perryer DG. Improvement of histological image interpretation for dichromatic observers. Proceedings of the 3rd ImageJ User and Developer Conference, Luxembourg, 27-29 Oct 2010.
  6. Landini G, Perryer DG. More on color blindness. Nature Methods 8 (11), 891, 2011. ( PDF)

Last updated on 20/Apr/2015.