MATLAB: How to count number of circles of a gray scale image

circle countImage Processing Toolbox

I want to count number of circles of a gray scale image. I have attached the sample image. I just want to count the number of circle of that image and fill the gaps of that circle. What should i do??

Best Answer

How many do you see? I see two circular black discs plus a bunch of other blobs that have irregular shapes, though some parts of their perimeters are circular.

See this link to split them apart, if you want to do that. http://www.mathworks.com/help/images/examples/marker-controlled-watershed-segmentation.html

Then you can count them with bwlabel();

[~, NumBlobs] = bwlabel(binaryImage);

If you want to, you can try imfindcircles. http://www.mathworks.com/matlabcentral/fileexchange/34365-circle-finder

http://blogs.mathworks.com/pick/2008/05/23/detecting-circles-in-an-image/

Another way is to use regionprops() to compute the area and perimeter of the blobs and compute the circularity and keep only blobs that are sufficiently close to being circular.

I can't do it all for you but if you have questions, attach whatever code you have.

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MATLAB: How can i separate all the connected regions in a binary image and display them individually.

Use bwlabel() and ismember

[labeledImage, numRegions] = bwlabel(binaryImage);
props = regionprops(labeledImage, 'Area')
% Compute all the areas.
allAreas = [props.Area]
% Display each blob in its own figure.
for k = 1 : numRegions
    thisRegion = ismember(labeledImage, k);
    figure;
    imshow(thisRegion);
    drawnow;
end

MATLAB: Number of Object in binary image

Try this:

bw = imread('bw.png');
if ndims(bw) > 1
	bw = bw(:,:,1);
end
% Threshold
bw = bw > 128;
subplot(1, 2, 1);
imshow(bw, []);
% Fill holes
bw = imfill(bw, 'holes');
% Get areas
props = regionprops(bw, 'Area');
sortedAreas = sort([props.Area], 'descend')
% Looks like we need to throw away any blobs less than 1000 pixels or so
bw = bwareaopen(bw, 1000);
subplot(1, 2, 2);
imshow(bw);
% Count the blobs
[labeledImage, numBlobs] = bwlabel(bw);
fprintf('Found %d shapes.\n', numBlobs);

Best Answer

Related Solutions

MATLAB: How can i separate all the connected regions in a binary image and display them individually.

MATLAB: Number of Object in binary image

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