Hi Juan, I tried computing `convex_hull_image` of `test_im` directly and as expected got the error you posted above. Then I tried to run `regionprops` on the `test_im` padded with 0s. This again threw the same error. But oddly so, direct computation of `convex_hull_image` of padded `test_im` does give a result! In spite of the traceback showing that the problem originated in `convex_hull_image` function. At least for the purposes of your problem you can probably compute the Solidity manually here. ``` In [27]: a = np.zeros((5,9), int) In [28]: a Out[28]: array([[0, 0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0, 0, 0]]) In [29]: a[1:-1, 1:-1] = test_im In [30]: a Out[30]: array([[0, 0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 1, 0, 0, 0], [0, 0, 0, 1, 1, 1, 1, 1, 0], [0, 1, 1, 1, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0, 0, 0]]) In [31]: b = convex_hull_image(a).astype(int) In [32]: b Out[32]: array([[0, 0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 1, 1, 1, 0, 0], [0, 0, 1, 1, 1, 1, 1, 1, 0], [0, 1, 1, 1, 1, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0, 0, 0]])``` Thanks, Chintak