gistfile1.txt

I  = imread('../assets/mixtexts1.bmp');

% S = qtdecomp(I, .27);

% blocks = repmat(uint8(0),size(S));

% for dim = [512 256 128 64 32 16 8 4 2 1];    
%   numblocks = length(find(S==dim));    
%   if (numblocks > 0)        
%     values = repmat(uint8(1), [dim dim numblocks]);
  
%     values(2:dim,2:dim,:) = 0;
  
%     blocks = qtsetblk(blocks,S,dim,values);
%   end
% end

% blocks(end,1:end) = 1;
% blocks(1:end,end) = 1;

% imshow(I), figure, imshow(blocks,[])



% function test

fhandle = @myfun;
S = qtdecomp(I,fhandle);
% S = qtdecomp(I,0.27);
blocks = repmat(uint8(0),size(S));

for dim = [512 256 128 64 32 16 8 4 2 1];    
  numblocks = length(find(S==dim));    
  if (numblocks > 0)        
    values = repmat(uint8(1),[dim dim numblocks]);
    values(2:dim,2:dim,:) = 0;
    blocks = qtsetblk(blocks,S,dim,values);
  end
end

blocks(end,1:end) = 1;
blocks(1:end,end) = 1;

imshow(I), figure, imshow(blocks,[])

function A = myfun(I)
	% I is the input matrix
	% there are k number of image blocks in I
	% each image block is m-by-m, m is unknown (but it's not important)

	varI = logical(zeros(1,size(I,3))); % create the output logical matrix, it has k number of elements where k is the number of image blocks
	threshold = 2.7;                    % variance threshold

	for i = 1:size(varI,2)
	    var_cur = var(var(double(I(:,:,i))))/numel(I);  % find the variance for the current image block

	    % If varI(i) = 1, this means we want to further split the current image block
	    varI(i) = logical(var_cur > threshold);         % further split the block if the variance is above the threshold
	end

	A = varI;