how to combine the image sub blocks back to the image???

i have divide the 256*256 image into 4 blocks and into the each block i have performed some operation. now i want that all the blocks will combine back to the image. how to to that. i have divided the image by the following code.

% Read the image from disk.

rgbImage = imread(fullFileName);

rgbImage=imresize(a,[512 512]);

% Enlarge figure to full screen.

set(gcf, 'units','normalized','outerposition',[0 0 1 1]);

drawnow;

% Get the dimensions of the image. numberOfColorBands should be = 3.

[rows columns numberOfColorBands] = size(rgbImage)

%==========================================================================

% The first way to divide an image up into blocks is by using mat2cell().

blockSizeR = 128; % Rows in block.

blockSizeC = 128; % Columns in block.

% Figure out the size of each block in rows.

% Most will be blockSizeR but there may be a remainder amount of less than that.

wholeBlockRows = floor(rows / blockSizeR);

blockVectorR = [blockSizeR * ones(1, wholeBlockRows), rem(rows, blockSizeR)];

% Figure out the size of each block in columns.

wholeBlockCols = floor(columns / blockSizeC);

blockVectorC = [blockSizeC * ones(1, wholeBlockCols), rem(columns, blockSizeC)];

% Create the cell array, ca.

% Each cell (except for the remainder cells at the end of the image)

% in the array contains a blockSizeR by blockSizeC by 3 color array.

% This line is where the image is actually divided up into blocks.

if numberOfColorBands > 1

% It's a color image.

ca = mat2cell(rgbImage, blockVectorR, blockVectorC, numberOfColorBands);

else

ca = mat2cell(rgbImage, blockVectorR, blockVectorC);

end

% Now display all the blocks.

plotIndex = 1;

numPlotsR = size(ca, 1);

numPlotsC = size(ca, 2);

for r = 1 : numPlotsR

for c = 1 : numPlotsC

fprintf('plotindex = %d, c=%d, r=%d\n', plotIndex, c, r);

% Specify the location for display of the image.

subplot(numPlotsR, numPlotsC, plotIndex);

% Extract the numerical array out of the cell

rgbBlock = ca{r,c};

imshow(rgbBlock); % Could call imshow(ca{r,c}) if you wanted to.

[rowsB columnsB numberOfColorBandsB] = size(rgbBlock);

% Make the caption the block number.

caption = sprintf('Block #%d of %d\n%d rows by %d columns', ...

plotIndex, numPlotsR*numPlotsC, rowsB, columnsB);

title(caption);

drawnow;

% Increment the subplot to the next location.

plotIndex = plotIndex + 1;

end

end

% Display the original image in the upper left.

subplot(4, 6, 1);

imshow(rgbImage);

title('Original Image');

this code belongs to imageAnalyst.

Answer 1

[sam alsalihy]

dear Sir/madam

after using the above code you can reconstruct the image by following code

[S A]=size(old_image);

T=blockSizeR*wholeBlockCols; 
  for v=1:wholeBlockRows
 
          if(v==1)
                            for r = 1 : S
                             for c = 1 : T

                              a(r,c)=old_image(r,c);
                             end
                            end
         else
                     v2=v-1;
                    cw=  S*v2+1;
                        for r = 1 : S
                            m=1;
                            for c = T*v2+1 : T*v
                                 a(cw,m)=old_image(r,c);
                                 m=m+1;
                            end
                                cw=cw+1;
                           end
     end 
  end