Accessing elements in a 2D array

[willy-bit]

I noticed there is a bug in the way you are accessing elements in the translation vector, t.
It is a 2D array, yet you are treating it as a single list.
Here is how you are accessing the elements: trans_params = np.array([w0, h0, s, t[0], t[1]]). This definitely raises a value error!

However, the correct way of accessing elements in a 2D array would be : trans_params = np.array([w0, h0, s, t[0][0], t[1][0]])

The bug is line 196 in the preprocess.py script under utils.