Rather than using one undefined model, Colorblind Simulator Pro is the only application that allows you to select one of four different models for simulation of CVD. Colorblind Simulator Free uses the default model. All models used are based on open source code. All models support sRGB, as Android uses the sRGB color space.
All models used in the Colorblind Simulator Pro app were tested using an automated version of the Farnsworth-Munsell D-15 Dichromatic Panel test. The purpose of the test was to determine if a simulation model generated responses that mimicked the same confusion as humans responses to the test.
The models provided in Pro are:
1) Meyer-Greenberg-Wolfmaier-Wickline (MGWW)
Meyer and Greenberg published their study in 1988. Wolfmaier wrote a Java applet in 1999. The code used in the app is based on WickLine's revisions in 2001. The responses generated by the MGWW model closely matched human responses under all test conditions.
2) Brettel-Vienot-Mollon (BVM)
The authors performed their study in 1997. The code used in the app is based on the code used in the Gimp photo editor. This model tends to not adequately distinguish between protanopia and deuteranopia. Of all the models, BVM responses were the farthest from human responses.
3) Machado-Oliveira-Fernandes (MOF)
MOF is the only model that us based on the stages theory of color vision. While based on the BVM model, the test results closely mimic human response. MOF is the only model that provides separate tables for different percentages of CVD. All other models use a generic algorithm. MOF is the default model.
4) ImageJ CVD Plug-in (ImageJ)
This plug-in is used in both ImageJ and Vischeck. The plug-in is based on MGWW, but uses precalculated tables. Consequently, the model is sensitive to any variation in test conditions.
Based on the sparse information available, this model provides a rough simulation of the gray world experienced by those who suffer from one of the four forms of monochromatic vision: rod, red, green, or blue.
In addition to providing different simulation models, Colorblind Simulator Pro allows you to vary:
1) The gamma to simulate different lighting conditions. The default gamma is 1.0, which is the system gamma. The Pro addition provides a feature that allows the gamma to vary according to the brightness setting.
2) The percentage of CVD. The range is from 0% loss to 100% loss, in steps if 10%. The default is 100%.
The Colorblind Simulator Free version does contain advertisements. The Pro version does not contain any advertising.
Simulation is a memory intensive task. While the applications check available memory before starting a simulation, the dynamic nature of memory usage can result in out of memory errors during simulation. This only occurs when simulating images, as every pixel requires transformation.