pseudo_col.m

clear all;
s=imread('photo.jpg');
s=rgb2gray(s);
s=double(s);
s=s/max(max(s));
r=zeros(size(s));
r(find(s<0.15))=1;
g=s;
b=s;
b(find(s>0.15))=.9;
ims=cat(3,r,g,b);
imshow(ims);