Quad tree decomposition using varience

Function performing quadtree decomposition of an image using varience criterion for splitting.

The function qtdecomp_var.m peformes quad tree decomposition of square gray-scale image using varience criperion. If an image block has varience greater or equal to the whole image varience (optionally weighted), then the block is split further. The weighting has an effect on the splitting similar to pre-processing the image using for example a median filter. For example usage see ex_qtdecomp_var.m.

% qtdecomp_var.m- quadtree decomposition based on variance
%**************************************************************************
% [S] = qtdecomp_var(I, var_weight)
%**************************************************************************
% INPUTS:
% I - gray scale square image
% var_weight- weight for the variance criterion [optional] (default is 1)
%**************************************************************************
% OUTPUTS:
% S- sparse matrix representing the quadtree structure after decomposition
% based on varience
%**************************************************************************
% NOTES: qtdecomp with custom function
%**************************************************************************
% EXAMPLES USAGE: see ex_qtdecomp_var.m