Connected components ocr in matlab(image processing) - matlab

Question

I am trying to get connected components of an image and then run ocr for each connected component.This is my code-
clc
image=imread('im.png');
image=imcomplement(image);
[imx imy]=size(image);
n1=zeros(imx,imy);
symb=zeros(imx,imy);
lin=zeros(imx,imy);
L = bwlabel(image,8) ;%Calculating connected components
mx=max(max(L));
for i=1:mx
[r,c] = find(L==i);
n1=zeros(imx,imy);
rc = [r c];
[sx sy]=size(rc);
for j=1:sx
x1=rc(j,1);
y1=rc(j,2);
n1(x1,y1)=1;
end
figure,imshow(n1);title('components');
r = ocr(n1,'TextLayout','Word')
n=strtrim(r.Text);
end
This is my input image-
One of the connected components which I get is this-
I get this when I display the components in 4th last line.But in the next line I dont get any result for the ocr of this component.So my question is why am I not getting ocr for this component whereas all other componets give some result in ocr.
If,instead of im.png I use this component as input in my very first line of the code-I get an ocr for this.Why is this happening?
Edit- If I use this component as input,I get the ocr.

Answer 1

I don't know exactly what you want to achieve (it was not very clear from your post). But if what you want is to extract the letters in a chemical formula the below code will do the trick.
I = imread('6oua6.png');
s = regionprops(~I,{'BoundingBox'});
for ii=1:numel(s)
bb = s(ii).BoundingBox;
if bb(4)<30 % enforce a limit to discard non-letters
ocr(I,s(ii).BoundingBox, 'TextLayout', 'Block' )
rectangle('Position',s(ii).BoundingBox+[-1 -1 2 2 ],'Edgecolor','y')
pause
end
end
The ocr will identify the letters correctly (at least from the image you supplied).
Binding them as further will just require you to construct some rules.
enjoy.