%%%%%%%%%%%% ENEE 631 HOMEWORK #2 %%%%%%%%%%%%%%%%%
% Contrast streching and histogram equalization.
%
% Daniel Garcia-Romero 2-21-2006
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

caves=imread('caves.jpg');
clouds=imread('clouds.jpg');
caves_yuv=rgb2ycbcr(caves);
caves_lum=caves_yuv(:,:,1);
clouds_yuv=rgb2ycbcr(clouds);
clouds_lum=clouds_yuv(:,:,1);


%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% Processing Clouds.jpg
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

% Histogram streching
[clouds_lum_streched] = histogram_streching_threshold(clouds_lum,.9,2.5,175,212);
figure;
subplot(2,2,1);
imshow(clouds_lum);
subplot(2,2,2);
imshow(clouds_lum_streched);
subplot(2,2,3);
imhist(clouds_lum);
subplot(2,2,4);
imhist(clouds_lum_streched);
imwrite(clouds_lum_streched,'clouds_lum_streched.jpg','jpeg');

% Histogram equalization
[clouds_lum_equalized] = histogram_equalization(clouds_lum);
figure;
subplot(2,2,1);
imshow(clouds_lum);
subplot(2,2,2);
imshow(clouds_lum_equalized);
subplot(2,2,3);
imhist(clouds_lum);
subplot(2,2,4);
imhist(clouds_lum_equalized);
imwrite(clouds_lum_equalized,'clouds_lum_equalized.jpg','jpeg');

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% Processing Caves.jpeg
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

% Histogram streching
[caves_lum_streched] = histogram_streching_threshold(caves_lum,4,1.5,27,75);
figure;
subplot(2,2,1);
imshow(caves_lum);
subplot(2,2,2);
imshow(caves_lum_streched);
subplot(2,2,3);
imhist(caves_lum);
subplot(2,2,4);
imhist(caves_lum_streched);
imwrite(caves_lum_streched,'caves_lum_streched.jpg','jpeg');

% Histogram equalization
[caves_lum_equalized] = histogram_equalization(caves_lum);
figure;
subplot(2,2,1);
imshow(caves_lum);
subplot(2,2,2);
imshow(caves_lum_equalized);
subplot(2,2,3);
imhist(caves_lum);
subplot(2,2,4);
imhist(caves_lum_equalized);
imwrite(caves_lum_equalized,'caves_lum_equalized.jpg','jpeg');