Character extraction - dots are recognized separately from the character - matlab

Question

I'm doing character recognition for a regional language. While extracting the image, the dots are being separately identified as characters.
%% Plot Bounding Box
for n=1:size(propied,1)
rectangle('Position',propied(n).BoundingBox,'EdgeColor','g','LineWidth',2)
end
hold off
%% Characters being Extracted
figure
for n=1:Ne
[r,c] = find(L==n);
n1=imagen(min(r):max(r),min(c):max(c));
imshow(~n1);
end
Original code: http://www.mathworks.com/matlabcentral/fileexchange/22922-image-segmentation-extraction

Answer 1

Since you are doing character/text recognition, you are more likely to want collections of words or lines of text, and not individual characters. And if you really want to do the latter, then it is more robust after you have identified the individual words.
So, the simplest approach here is using the standard morphological opening (assuming the text is black, otherwise use closing) operator. Start with a large horizontal structuring element (SE). Applying a opening with this SE will divide your image in lines of text. In each line you use a shorter horizontal SE to obtain the individual words. Then for each word you consider a vertical SE for opening such that it joins accents and other typographical details.
For example, here is an input image, its opening with a horizontal SE of radius 35, the opening with a horizontal SE of radius 7, and a opening with a vertical SE of radius 7.
I didn't apply the third operation in isolated components, but you should do so to not risk joining two lines of text. And this is all assuming straight horizontal lines of text, of course. Drawing the bounding boxes on this final image gives the result you are after:
Note that some letters ("ty", and "ny") were connected in the beginning, so they appear as a single letter in this output. This is a separate problem to be handled, which might or not be a concern for you.