Object-counting in image processing.

Question

Kangkan 2013-10-20

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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/90873-object-counting-in-image-processing

评论： Image Analyst 2020-10-28

I am doing a project on object-counting from images. For that, I have taken two images- one is the background containing no objects and the other containing some objects(toy-cars) over it.

Background Image:

------------------------------------------------------------

Image with objects over it:

The difference-image between the two images is taken and converted to black-and-white using a threshold value. The problem is that some of the pixels inside the objects match with the background and so these pixels are also getting subtracted completely and as a result, some black pixels are occurring inside the objects as you can see from the b/w image below and so the objects are getting divided into parts.

I need each object to occur as one object so that we get the exact no of objects. Can someone please help me regarding this.

The code I have used is below:

I = imread('Snap5.png');

J = imread('bg1.png');

K = imabsdiff(I,J);

th = graythresh(K);

L = im2bw(K,th);

[LabeledIm,ConnectedObj] = bwlabel(L,4);

coloredLabels = label2rgb (LabeledIm, 'hsv', 'k', 'shuffle');

ConnectedObj

figure,

subplot(221), imshow(K), title('Difference'),

subplot(222), imshow(L), title('Thresholded BW'),

subplot(223), imshow(coloredLabels), title('Color-labeled Objects');

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Image Analyst 2020-9-18

编辑：Image Analyst 2020-9-18

在 MATLAB Online 中打开

"Project Traffic", 3.5 years old so I realize you probably won't answer but re-reading the question, when you say "can you please upload the exact matlab code for counting the objects even if there is another object within the same object and give a count of one" it sounds ambiguous. I'm unsure if you have an object containing another object, like a bullseye target,

do you want that to count as one white object or two? Normally bwlabel() whould give a count of 2.

[labeledImage, numRegions] = bwlabel(binaryImage);

If you want it to count as 1, then you can either fill the outer objects and label

binaryImage = imfill(binaryImage, 'holes');
[labeledImage, numRegions] = bwlabel(binaryImage);

However this would change the measurements returned by regionprops since now the blob's area is different - it's just one giant disc instead of a thin ring. Or you could get rid of "interior" blobs using some morphological tricks so that there is just one thin white ring. Let me know if you need that.

Jeje Ahmad 2020-10-28

@KangKan

Image Analyst 2020-10-28

Kangkan hasn't been here in 7 years, but you can sure give it try. Just copy, paste, and change image filename, and run.

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Answer 1

Image Analyst 2013-10-20

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/90873-object-counting-in-image-processing#answer_100320

在 MATLAB Online 中打开

Replace these two lines:

L = im2bw(K,th);
[LabeledIm,ConnectedObj] = bwlabel(L,4);

with these

binaryImage = im2bw(K,th);
binaryImage  = imclose(binaryImage, true(5)); % Close gaps and connect nearby blobs.
binaryImage = bwconvhull(binaryImage); % Make shapes convex and fill holes.
[LabeledIm,ConnectedObj] = bwlabel(binaryImage,4);