lacunarity_glbox.m

%%
% Author: Tegy J. Vadakkan
% Date: 09/08/2009
% Gliding box lacunarity algorithm based on the ideas presented in the
% paper by Tolle et al., Physica D, 237, 306-315, 2008
% input is the binary file with 0's and 1's. 0's represent the holes or the
% lacunae
% the output M gives the lacunarity at various box lengths (edge sizes are multiples of 2)
clc;
clear all;
close all;
%%
indata=inputdlg({'input filename'});
a = imread(indata{1});
[rows, cols] = size(a);
a = 1 - a;
%%
n = 2;
while(n <= rows)
nn = n-1;
rnn = rows - nn;
index = uint8(log2(n));
count(index)= power(rnn,2);
sigma(index) = 0.0;
sigma2(index) = 0.0;
for i=1:rnn
    for j=1:rnn
        sums = sum(sum(a(i:i+nn,j:j+nn)));
        sigma(index) = sigma(index) + sums;
        sigma2(index) = sigma2(index) + power(sums,2);
    end
end
n = n * 2;
end
%%
for i=1:index
    M(i,1)= (count(i)*sigma2(i))/(power(sigma(i),2));
end