% Problem 2
% =========
I = [12 6 5 13 14 14 16 15 ; ...
  11 10 8 5 8 11 14 14 ; ...
  9 8 3 4 7 12 18 19 ; ...
  10 7 4 2 10 12 13 17 ; ...
  16 9 13 13 16 19 19 17 ; ...
  12 10 14 15 18 18 16 14 ; ...
  11 8 10 12 14 13 14 15 ; ...
  8 6 3 7 9 11 12 12];

[g,T,pin,pout] = heq_full(I,20);

% Problem 3
% =========
c = imread('cameraman.tif');
[x map] = gray2ind(c);
[xeq,t,pin,pout] = heq_full(x,256);
figure(1);clf
subplot(221);imshow(x);
title('Original');
subplot(222);stem(0:255,pin);
title('Original histogram')
subplot(223);imshow(uint8(xeq));
title('Equalized');
subplot(224);stem(0:255,pout);
title('Equalized histogram')

print -djpeg prob3.jpg

% Problem 4
% =========
gam1 = .3;   c1 = 255^(1-gam1);
gam2 = 1.5;  c2 = 255^(1-gam2);


r = (0:255)';

figure(1);clf;
plot(r,c1*r.^gam1,'-',r,c2*r.^gam2,'--');
legend('\gamma = 0.1','\gamma  = 1.5')
xlabel('r');
ylabel('s')

print -djpeg prob4.jpg