error in detecting components using bwlabel

I used bwlabel for detecting connected components but i got error output i.e 3 objects are detected instead of 8. I am attaching input image. Expecting your suggestion.

Answer 1

[Walter Roberson]

bwlabel assumes that the white pixels are where the data is and that the black pixels are holes. When you have black text on a white background you need to invert the image.

[SHOBA MOHAN]

Thanks Walter. After using imcomplement it detects all the objects. but the output seems blurred one. How can i make exact detection of objects i am using the below code.

ImgPlate=imread('ImgPlate.jpg');
 ImgPlate=im2bw(ImgPlate);
% ImgPlate=bwareaopen(ImgPlate,4);
ImgPlate=imcomplement(ImgPlate);
figure,imshow(ImgPlate);
[L,Ne]=bwlabel(ImgPlate);
for n=1:Ne
  [r,c] = find(L==n);   
  n1=picture(min(r):max(r),min(c):max(c));   %picture command crops nth object from L
  n1=imresize(n1,[42,24]);     %in database size is 42,24 so it is resized so that we can match it with the database
 figure,imshow(n1);
end

[Walter Roberson]

I would suggest that you do a bwclose() before doing the labeling, in order to join together sections that are close together such as the two parts of the accessibility symbol.

You are starting with a JPEG image, so you have to live with blurring. JPEG in the default lossless mode always blurs straight edges.

[SHOBA MOHAN]

Thanks Walter. I will try with your inputs.

[Image Analyst]

Or you could sum the image vertically to find the gaps between the symbols.