MATLAB: Is it possible to fill the kink at 4 o’clock in this image

Question

I have a BW image that's nearly circular, save the dent on the right side. Is it possible to fill this dent?

Also, is the segmentation on the second image good? Could you provide your thoughts?

Thanks!

Answer 1

I'd call imfill, then bwareafilt(mask, 1) to get the largest blob.

mask = imfill(mask, 'holes');
mask = bwareafilt(mask, 1);

Then call bwboundaries and use the FAQ to fit it to a circle.

boundaries = bwboundaries(mask);
boundaries = boundaries{1};
x = boundaries(:, 2);
y = boundaries(:, 1);

https://matlab.fandom.com/wiki/FAQ#How_can_I_fit_a_circle_to_a_set_of_XY_data.3F

Then use poly2mask to make a mask of the perfect/fit circle and AND the two

[rows, columns] = size(mask);
circleMask = poly2mask(xCircle, yCircle, rows, columns);
outputMask = mask & circleMask;