pkg load image
clear
clc

I = imread('Lena256color.jpg');
I2 = uint8(zeros(256,256,3));
I3 = uint8(zeros(256,256,3));
I4 = uint8(zeros(256,256,3));

I2(:,:,1) = I(:,:,1)/3;
I2(:,:,2) = I(:,:,2);
I2(:,:,3) = I(:,:,3)*4;

I3(:,:,1) = I(:,:,1)*2;
I3(:,:,2) = I(:,:,2);
I3(:,:,3) = I(:,:,3)/2;

I4(:,:,1) = I(:,:,1)/3;
I4(:,:,2) = I(:,:,2)*2;
I4(:,:,3) = I(:,:,3)/2;

subplot(2,2,1), imshow(I,[0 255]), title('Original')
subplot(2,2,2), imshow(I2,[0 255]), title('Cool')
subplot(2,2,3), imshow(I3,[0 255]), title('Warm')
subplot(2,2,4), imshow(I4,[0 255]), title('Marsian')