% 灰度圖像偽彩色顯示(十二色)  s040
I40=imread('1.jpg');
I400=rgb2gray(I40);
[m,n]=size(I400);
for i=1:m
    for j=1:n
        if I400(i,j)<21
            a1(i,j)=255;
            a2(i,j)=0; 
            a3(i,j)=0;
        elseif I400(i,j)<42
            a1(i,j)=255;
            a2(i,j)=127; 
            a3(i,j)=0;
        elseif I400(i,j)<63
            a1(i,j)=127;
            a2(i,j)=255; 
            a3(i,j)=0;
        elseif I400(i,j)<84
            a1(i,j)=0;
            a2(i,j)=255; 
            a3(i,j)=0;
        elseif I400(i,j)<105
            a1(i,j)=0;
            a2(i,j)=255; 
            a3(i,j)=127;
        elseif I400(i,j)<126
            a1(i,j)=0;
            a2(i,j)=127; 
            a3(i,j)=255;
        elseif I400(i,j)<147
            a1(i,j)=0;
            a2(i,j)=0; 
            a3(i,j)=255;
        elseif I400(i,j)<168
            a1(i,j)=127;
            a2(i,j)=0; 
            a3(i,j)=255;
        elseif I400(i,j)<189
            a1(i,j)=255;
            a2(i,j)=0; 
            a3(i,j)=127;
        elseif I400(i,j)<210
            a1(i,j)=256;
            a2(i,j)=127; 
            a3(i,j)=127;
        elseif I400(i,j)<231
            a1(i,j)=127;
            a2(i,j)=255; 
            a3(i,j)=127;
        else
            a(i,j,1)=1271;
            a(i,j,2)=127; 
            a(i,j,3)=255;
        end
    end
end
figure,imshow(a)