How I can detect this ball in the image

Answer 1

[jonas]

For circles you can simply use the imfindcircles function.

I=imread('crop.jpg');
imshow(I);hold on
[centers rr] = imfindcircles(I,[200 500],'sensitivity',0.99)
viscircles(centers,rr)

See attachment for result.

[stellarpranav]

Thank you so much !! But actually the problem is what will happen when the object is not circle(i.e any random shape). We can't detect it through RGB or hsv, as it is having a definite pattern with changing RGB. Then how to detect such type of object in an image?

[Image Analyst]

What are you trying to detect. Of course the segmentation algorithm will be different. You can't have just one do-all segmentation algorithm for absolutely everything. All you gave was one example so that's all that jonas could solve. But now you have opened it up to any kind of object whatsoever, of any color whatsoever, of any shape whatsoever. This cannot be answered except to say that a single segmentation algorithm cannot locate every single possible object whatsoever. Maybe if you have a moving scene, like a video, you can use some of the tracking capabilities of the Computer Vision System Toolbox.

[stellarpranav]

I want to detect this ball, by template matching alogrithm rather than detecting it as a circle.

[Image Analyst]

Try deep learning. https://www.mathworks.com/solutions/deep-learning.html?s_tid=hp_brand_deeplearning

Or Hu's moments: http://www.youtube.com/watch?v=Nc06tlZAv_Q

Or normalized cross correlation (see attachment).

Or SURF or other things in the Computer Vision System Toolbox. https://www.mathworks.com/products/computer-vision.html