Change corners from image

Hello everyone!

I have this figure I'm working on, shown below, and I want to remove those upper and below left black corners or even change them from black to white, but I'm not finding any solution...

Also, since I'm dealing with different versions of this image (rotated, different sizes, I wanted to make this process as general as possible. Anyone has any idea?

Thanks!

[KSSV]

Which black corners? The left one?

[Iugo]

@KSSV Yes, exactly!

Answer 1

[Walter Roberson]

img = imread('https://www.mathworks.com/matlabcentral/answers/uploaded_files/661015/image.png');
imshow(img);
title('original RGB')

BW = imbinarize(rgb2gray(img));
imshow(BW)
title('binary');

mask = ~bwareafilt(~BW, 1);
imshow(mask)
title('mask with cleared boundary')

[Iugo]

Thank you so much @Walter Roberson, that's it!!