JPG screenshots of the ambiguous superposition of working images are not working images.
% the only given image is a screenshot
% it's impossible to tell what the original shapes were
% the claim of 2 intersection points appears to be plainly false
% i'm just going to guess and make my own example images
A = imread('shape_a.png');
B = imread('shape_b.png');
% binarize both images somehow
% i'm already working with single-channel images
A = imbinarize(A);
B = imbinarize(B);
% what is the area of interest?
% is it inside the perimiter or outside?
% does it include the perimeter?
% does it exclude the perimeter?
% i assume it's the interior region including the perimeter
% and that both perimeters are closed paths
A = imfill(~A,'holes'); % fill the perimeters
B = imfill(~B,'holes');
% now both images are binary masks
% unambiguously describing two regions
% assuming that the two images are already registered
% find their intersection
C = A & B;
% area of the images and intersection in px
% convert to whatever units are relevant
areaA = nnz(A)
areaB = nnz(B)
areaC = nnz(C)
% compare the images
imshow([A B C])
