% cleangrid - clean up matrix with grid line of same value
%
% Usage: 
%       [cleanMatrix,rowIndex,colIndex] = cleangrid(gridMatrix,gridValue)
%
%
% Arguments: 
%       gridMatrix  - the matrix to be cleaned
%       gridValue   - the grid value
%
% Output:
%       cleanMatrix - the cleaned up matrix, smaller size
%       rowIndex    - the row index that grid lines have been cleaned
%       colIndex    - the column index that grid lines have been cleaned
%
% See also addgrid.m

% Author: 
% Tzu Yen Wong
% wongt AT csse DOT uwa DOT edu DOT au
% Department of Computer Science & Software Engineering
% The University of Western Australia
%
% Nov 2003
% June 2004 change email address to fight SPAM!!!

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function [cleanMatrix,rowIndex,colIndex] = cleangrid(gridMatrix,gridValue)

grid = (gridMatrix==gridValue);        

colIndex = find(sum(~grid,1)==0);   colIndex = colIndex(:)';
rowIndex = find(sum(~grid,2)==0);   rowIndex = rowIndex(:)';

lengthc = length(colIndex);
lengthr = length(rowIndex);

for ii=lengthr:-1:1,
    grid_ii = rowIndex(ii);
    gridMatrix(grid_ii:end-1,:) = gridMatrix(grid_ii+1:end,:);
end    
    
for jj=lengthc:-1:1,
    grid_jj = colIndex(jj);
    gridMatrix(:,grid_jj:end-1) = gridMatrix(:,grid_jj+1:end);
end        

cleanMatrix = gridMatrix(1:end-lengthr,1:end-lengthc);