Looking to identify a football from an image

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I currently have a still image of a football about to be kicked. I would like to identify the ball and it's center.

Answers (1)

Kevin Holly
Kevin Holly on 30 Sep 2022
RGB = imread('YourImage.png');
% Convert RGB image to lab space
I = rgb2lab(RGB);
% Apply thresholds
BW = (I(:,:,1) >= 14.5 ) & (I(:,:,1) <= 89.77) & ...
(I(:,:,2) >= 0.12) & (I(:,:,2) <= 12.5) & ...
(I(:,:,3) >= 3.8) & (I(:,:,3) <= 33.0);
% Open mask
se = strel('disk', 13,0);
BW = imopen(BW, se);
% Filter out smaller objects
BW=bwareafilt(BW,[50000 Inf]);
% Find Centroid and Area of object
rp = regionprops(BW,"Centroid","Area")
rp = struct with fields:
Area: 58864 Centroid: [644.7752 215.7900]
% Display masked image for verfication purposes
maskedRGBImage = RGB;
maskedRGBImage(repmat(~BW,[1 1 3])) = 0;
imshow(maskedRGBImage)
% Add marker on centroid
hold on
scatter(rp.Centroid(1),rp.Centroid(2),'b','filled')
  1 Comment
Michael Sposato
Michael Sposato on 5 Oct 2022
I also need this to work for other images as well. What is there to change to do this? I attached another sample image as well.
Also how is the centroid calculated? Is it by the extremes or by matlab calculating the area of the ellipse?

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