MATLAB: How can i divide green HL2 component into four blocks??

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My project is on digital color image watermarking!!the size of image that i use as cover image is 512*512. for embedding purposr first i apllly 2 level dwt and the i want to to divide green hl2 component into 4 blocks.the code is here.
this statment is use for calling the thefunction
 [ upperHalfA1,lowerHalfA1,upperHalfA2,lowerHalfA2 ] = Dividev2( hl2);
/// where division function Dividev2 code is here. ////
function [ upperHalf1,lowerHalf1,upperHalf2,lowerHalf2 ] = Dividev2( A)
%UNTITLED4 Summary of this function goes here
%   Detailed explanation goes here
% obtain size of image.
[rows, columns] = size(A);
middleColumn = int32(columns/2);
middleRow = int32(rows/2);
% Split them up.
% out = mat2cell(image,ones(256/32,1)*32,ones(256/32,1)*32,3);
upperHalf1 = A(1:middleRow, 1:middleColumn);
lowerHalf1=A( middleRow+1:end,1:middleColumn);
% Display them.
% subplot(2, 2, 1);
% imshow(upperHalf1);
% title('Upper Left Half', 'FontSize', 15);
% subplot(2, 2, 3);
% imshow(lowerHalf1);
% title('Lower Left Half', 'FontSize', 15);
upperHalf2 = A(1:middleRow, middleColumn+1:end);
% subplot(2, 2, 2);
% imshow(upperHalf2);
% title('Upper Right Half', 'FontSize', 15);
lowerHalf2=A( middleRow+1:end, middleColumn+1:end);
% subplot(2, 2, 4);
% imshow(lowerHalf2);
% title('Lower Right Half', 'FontSize', 15);
%reB=[upperHalf1,upperHalf2];
%reA=[lowerHalf1,lowerHalf2];
%RECnst=[reB;reA];
%figure
%imshow(RECnst)
end
but this code gives wrong size
please help me how can i divide green HL2 component in four blocks on matlab.

Best Answer

HL2_11 = HL2(1:end/2,1:end/2);
HL2_21 = HL2(end/2+1:end,1:end/2);
HL2_12 = HL2(1:end/2,end/2+1:end);
HL2_22 = HL2(end/2+1:end, end/2+1:end);
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