function protRGB = protanopia(normalRGB)
%PROTANOPIA   Simulate an image with L-cone deficiency (protanopia).
%
%   PROT = PROTANOPIA(RGB)
%
%   Reference: http://www.tsi.enst.fr/~brettel/CRA24/table2.html

cmaps = load('color_anomalies.mat');

% Convert the RGB image to an indexed image using the normal colormap.
normalInd = rgb2ind(normalRGB, cmaps.normal ./ 255);

% Convert back to an RGB image using the anomalous colormap.
protRGB = ind2rgb(normalInd, cmaps.prot ./ 255);