imbase = ['../text/images/'];
% Get some images
bi = imread([imbase,'circles.tif']);     % Binary
gs = imread([imbase,'cameraman.tif']);   % Grayscale
co = imread([imbase,'flowers.tif']);     % RGB color
[in inmap] = imread([imbase,'emu.tif']); % Indexed color

% Let's look at their types and sizes
whos

figure(1); clf

% Let's see how image command works for grayscale image
image(gs)
impixelinfo
% Play with colormaps
colormap(jet(256))
colormap(jet(64)) % Why is everything red?
colormap(hot(256))
colormap(gray(256))  % Gray scale
colormap(flipud(gray)) % Negative gray scale.  What does flipud do?

% Now try a color image
figure(1); clf
image(co)

% Explore imshow function
figure(1); clf
imshow(gs) % Works fine for uint8 data
% Now add some noise
% Convert gs to double and add random component
gs2 = double(gs)+100*randn(size(gs));
% Display the results
imshow(gs2) % Major problems
% Rescale
m = min(min(gs2));
M = max(max(gs2));
s = 1/(M-m);
gs2_scaled = s*(gs2-m);
imshow(gs2_scaled)

% Bitplanes
c = imread('../text/images/caribou.tif');
% Get all eight bitplanes
b0 = logical(bitget(c,1));
b1 = logical(bitget(c,2));
b2 = logical(bitget(c,3));
b3 = logical(bitget(c,4));
b4 = logical(bitget(c,5));
b5 = logical(bitget(c,6));
b6 = logical(bitget(c,7));
b7 = logical(bitget(c,8));
% ... and plot them
figure(1);clf
subplot(421);imshow(b0);title('b0')
subplot(422);imshow(b1);title('b1')
subplot(423);imshow(b2);title('b2')
subplot(424);imshow(b3);title('b3')
subplot(425);imshow(b4);title('b4')
subplot(426);imshow(b5);title('b5')
subplot(427);imshow(b6);title('b6')
subplot(428);imshow(b7);title('b7')


% Use of "for" loops for performing image operations
[nr nc] = size(c);
% Not necessary to pre-allocate output image, but a good idea if you know
% the size.  Tends to speeed tings up.
bitplane3 = zeros(nr,nc); % Could use zeros(size(c)) if you wished
% Use variables idxr and idxc to index fros and columns
% Notes:
%    - Nested for loop structure
%    - Syntax of the loop
for idxr = 1:nr
  for idxc = 1:nc
    bitplane3(idxr,idxc) = logical(bitget(c(idxr,idxc),3));
  end
end

% Now the functional approach
tic
bitplane3a = bitplane(c,3);
toc
tic
bitplane3a = bitplane_no_for(c,3);
toc
% Check the results
max(max(bitplane3-bitplane3a))