extracting rgb from each block of an image in matlab

we divided an image of size 800*600 into 5 blocks using function "mat2cell" and i got output as "Columns 1 through 3

    [60x80 uint8]    [60x80 uint8]    [60x80 uint8]
    [60x80 uint8]    [60x80 uint8]    [60x80 uint8]
    [60x80 uint8]    [60x80 uint8]    [60x80 uint8]
    [60x80 uint8]    [60x80 uint8]    [60x80 uint8]
    [60x80 uint8]    [60x80 uint8]    [60x80 uint8]

Columns 4 through 5                       

    [60x80 uint8]    [60x80 uint8]     "
    [60x80 uint8]    [60x80 uint8]
    [60x80 uint8]    [60x80 uint8]
    [60x80 uint8]    [60x80 uint8]
    [60x80 uint8]    [60x80 uint8]

now i want to extract rgb from each block of the image.. plz help..

Answer 1

[Matt Kindig]

What was the original size of the matrix? From your output, it looks like the matrix had a third dimension of 1. For an image to be RGB, the third dimension must be 3, i.e.

[m n p] = size(IMAGE)
 %p must be 3 for RGB

So I'm not sure how it's possible to do what you are trying to do.

Answer 2

[Image Analyst]

See this demo and you will know how to do it:

clc;    % Clear the command window.
close all;  % Close all figures (except those of imtool.)
imtool close all;  % Close all imtool figures.
workspace;  % Make sure the workspace panel is showing.
fontSize = 20;

% Read in a standard MATLAB color demo image.
folder = fullfile(matlabroot, '\toolbox\images\imdemos');
baseFileName = 'peppers.png';
fullFileName = fullfile(folder, baseFileName);
% Get the full filename, with path prepended.
fullFileName = fullfile(folder, baseFileName);
if ~exist(fullFileName, 'file')
  % Didn't find it there.  Check the search path for it.
  fullFileName = baseFileName; % No path this time.
  if ~exist(fullFileName, 'file')
    % Still didn't find it.  Alert user.
    errorMessage = sprintf('Error: %s does not exist.', fullFileName);
    uiwait(warndlg(errorMessage));
    return;
  end
end
rgbImage = imread(fullFileName);
% For demo purposes for Deepak, let's resize it to be a multiple of 25;
rgbImage = imresize(rgbImage, [100 150]);
% Get the dimensions of the image.  numberOfColorBands should be = 3.
[rows columns numberOfColorBands] = size(rgbImage)
blockSize = 25;
ca = mat2cell(rgbImage,blockSize*ones(1,size(rgbImage,1)/blockSize),blockSize*ones(1,size(rgbImage,2)/blockSize),3);
plotIndex = 1;
for r = 1 : size(ca, 1)
  for c = 1 : size(ca, 2)
    fprintf('c=%d, r=%d\n', c, r);
    subplot(4, 6, plotIndex);
    imshow(ca{r,c});
    plotIndex = plotIndex + 1
  end
end

% Display the original image in the upper left.
subplot(4, 6, 1);
imshow(rgbImage);
title('Original Image');
% Enlarge figure to full screen.
set(gcf, 'units','normalized','outerposition',[0 0 1 1]);