Extract watermark from any size image ?

I wanna to generalize this extraction code to work to any image size , It was basically for only extraction 512*512 Image , I waana make it work for any Image size so I can later on extract the watermark from comressid image and cropped image could any one help, please? Here is the code

    function [wm]=exwmarkGeneral()
    % exwmark will extract the watermark which were
    % embedded by the wtmark function

    % embimg    = Embedded image
    % wt        = Extracted Watermark
    embimg=imread('cout.jpg');
    [rows, columns , numberOfColorBands] = size(embimg);
    %     figure(1),imshow(EmbeddedImage),title('EmbeddedImage');
     m=embimg;   
        %==========================================================================
        blockSizeR = 8; % Rows in block.
        blockSizeC = 8; % Columns in block.
        wholeBlockRows = floor(rows / blockSizeR);
        blockVectorR = blockSizeR * ones(1, wholeBlockRows); 
        wholeBlockCols = floor(columns / blockSizeC);
        blockVectorC = blockSizeC * ones(1, wholeBlockCols);
        ca=mat2cell(m,blockVectorR,blockVectorC);
        numplotR=size(ca,1);
        numplotC=size(ca,2);

    %%%%%%%%%%%%%%%%%To divide image in to 4096---8X8 blocks %%%%%%%%%%%%%%%%%%
    k=1; dr=0; dc=0;
    % dr is to address 1:8 row every time for new block in x
    % dc is to address 1:8 column every time for new block in x
    % k is to change the no. of cell
    for ii=1:8:numplotR % To address row -- 8X8 blocks of image
        for jj=1:8:numplotC % To address columns -- 8X8 blocks of image
            for i=ii:(ii+7) % To address rows of blocks
                dr=dr+1;
                for j=jj:(jj+7) % To address columns of block
                    dc=dc+1;
                    z(dr,dc)=m(i,j);
                end
                dc=0;
            end
            x{k}=z; k=k+1;
            z=[]; dr=0;
        end
    end
    nn=x;

    %%Extract water mark %%
    wm=[]; wm1=[]; k=1; wmwd=[]; wmwd1=[]
    while(k<1025)
        for i=1:32
        kx=x{k}; % Extracting Blocks one by one
        dkx=blkproc(kx,[8 8],@dct2); % Applying Dct
        nn{k}=dkx; % Save DCT values in new block to cross check

        %%Change me for pixel location
        wm1=[wm1 dkx(8,8)]; % Forming a row of 32 by 8,8 element

        % Extracting water mark without dct
         wmwd1=[wmwd1 kx(8,8)];
          k=k+1;
        end
        wm=[wm;wm1]; wm1=[]; % Forming columns of 32x32
        wmwd=[wmwd;wmwd1]; wmwd1=[];
    end

    for i=1:32
        for j=1:32
            diff=wm(i,j) ;
            if diff >=0
                wm(i,j)=0;
            elseif diff < 0
                wm(i,j)=1;
            end
        end
    end

    wm=wm';
    imwrite(wm,'wexg.jpg');
    imshow('wexg.jpg');

[Eliza]

Here is the error happens

Index exceeds matrix dimensions.
Error in exwmarkGeneral (line 47)
    kx=x{k}; % Extracting Blocks one by one

Answer 1

[Saira Khalid]

blockSizeR = 8; % Rows in block.
      blockSizeC = 8; % Columns in block.
      wholeBlockRows = floor(rows / blockSizeR);
      blockVectorR = blockSizeR * ones(1, wholeBlockRows); 
      wholeBlockCols = floor(columns / blockSizeC);
      blockVectorC = blockSizeC * ones(1, wholeBlockCols);
      ca=mat2cell(m,blockVectorR,blockVectorC);
      numplotR=size(ca,1);
      numplotC=size(ca,2);
i think there is no need of this code .. Make it comment and run

and also Show your embedding code here..