grow_region.m

% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% % Copyright 2016 Mayuresh Sarpotdar
% % 
% %    Licensed under the Apache License, Version 2.0 (the "License");
% %    you may not use this file except in compliance with the License.
% %    You may obtain a copy of the License at
% % 
% %        http://www.apache.org/licenses/LICENSE-2.0
% % 
% %    Unless required by applicable law or agreed to in writing, software
% %    distributed under the License is distributed on an "AS IS" BASIS,
% %    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
% %    See the License for the specific language governing permissions and
% %    limitations under the License.
% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

function reg_img = grow_region(img,reg_img,row,col,thresh,region_count)
% 8 neighbour region growing to detect slant lines too 

[r c] = size(img);
neighb = [0,1; 1,0; 0,-1; -1,0; 1,1; 1,-1; -1,-1; -1,1];
reg_img(row,col) = region_count;
for i=1:8
    rown = row+neighb(i,1); coln = col+neighb(i,2);
    if (rown>0 && coln>0 && rown<r && coln<c)
        if(reg_img(rown,coln)==0 && img(rown,coln)>thresh)
            reg_img(rown,coln) = region_count;
            reg_img = grow_region(img,reg_img,rown,coln,thresh,region_count);
        end
    end
end
end