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