% author: M.M.Haji
% email : mehdi.haji@gmail.com
%
function y = remove_nontext1(x_in)
% remove non-text components from the image x, using wavelet transform
% see "Fast Text Segmentation Using Wavelet for Document Processing" by 
% S. Deng and S. Latif for more details.
%
% example:
%
% x = imread('image031.jpg');
% imshow(remove_nontext1(x))

if ndims(x_in) == 3
    x_in = rgb2gray(x_in);
end

[nr nc] = size(x_in);

[C,S] = wavedec2(x_in,2,'haar');

% cA2 = appcoef2(C,S,'haar',2);
% cH2 = detcoef2('h',C,S,2);
% cV2 = detcoef2('v',C,S,2);
cD2 = detcoef2('d',C,S,2);

fun = inline('sum(abs(x(:)))');
E1 = blkproc(cD2,[3 3],fun);

[IDX C]= kmeans([E1(:)],2,'rep',4,'EmptyAction','drop','Display','off');

if( norm(C(1,:)) > norm(C(2,:)) )
    IDX(find(IDX==1)) = 1;
    IDX(find(IDX==2)) = 0;
else
    IDX(find(IDX==1)) = 0;
    IDX(find(IDX==2)) = 1;
end

IDX = logical(reshape(IDX,size(E1)));

imwrite(IDX,'tmp.bmp');

% post processing:
dos('rbsmooth tmp.bmp tmp.bmp 1 10');
L = imread('tmp.bmp');
L = imclose(L,strel('rect',[1 3]));
L = imopen(L,strel('rect',[3 1]));
L = imopen(L,strel('rect',[1 3]));
L = imdilate(L,strel('rect',[3 3]));
L = imdilate(L,strel('rect',[1 3]));

% [L2 NUM] = bwlabel(L,8);
% B = imfeature(L2,'BoundingBox');
% for i1 = 1:NUM
%     tmp = B(i1).BoundingBox;
%     sx = ceil(tmp(1));
%     sy = ceil(tmp(2));
%     w = floor(tmp(3));
%     h = floor(tmp(4));
%     
%     L(sy:sy+h,sx:sx+w) = 1;
% end

y = imresize(L,12);
y = y(1:nr,1:nc);