Exa = 3;

switch Exa
case 1
  imfinfo('WallaceGromit.png')       % show information on the file
  im = imread('WallaceGromit.png');  % load the file
  size(im)
  figure(1)
  imshow(im)                         % display the original picture
case 2
  imGray = rgb2gray(im);             % convert to a grayscale image
  % read out the Red, Green and Blue components, then display
  imR = im(:,:,1); imG = im(:,:,2); imB = im(:,:,3);
  figure(2)
  subplot(2,2,1); imshow(imGray)
  subplot(2,2,2); imshow(imR)
  subplot(2,2,3); imshow(imG)
  subplot(2,2,4); imshow(imB)
case 3
  F = fspecial('average', 12);
  imFilter = imfilter(im, F);
  figure(3)
  imshow(imFilter)
end%switch