MATLAB: From points to closed contour

Question

I have 6 points as shown in the picture above.

Can I make a closed contour from the 6 points as shown below?

I've tried to use creating ellipse and imfill() but they didn't work.

Thank you.

Answer 1

Try this

im = im2double(imread('image.jpeg'));
im_gray = rgb2gray(im);
im_gray = imbinarize(im_gray)*1;
[r,c] = find(im_gray==1);
points = [c r];
p = convhull(points);
points = points(p, :).';
poly_points = points(:).';
im_gray = insertShape(im_gray, 'FilledPolygon', poly_points, ...
    'Color', [1 1 1], ...
    'Opacity', 1, ...
    'SmoothEdges', false);
imshow(im_gray);