GitLab

The file `test.py` is now moved into the test folder and pytest directives have been added.

Now it explicitly checks for there to be an all-0 pixel meaning
"unknown" and prints an info about it if it finds one.
This is a try at fixing #30 and #31.

The exception is now correctly propagated instead.

add grayscale image example

Specifically, about what the compatibility and kernel parameters are, about missing the weights, and some pointers about learning.

There was a sudden interest in this, both via issues (#23) and direct e-mail almost simultaneously. Odd 😄

Clearer and more unified unary utilities.

Examples fixFixes to the examples, it's only one now, but it's better!

Fix off-by-one error in `compute_unary` utility function.

Due to the special case of '0' indicating no label and being assigned uniform probs, and M being the number of labels not including this I believe the original function was not correct, as the highest label would be out of bounds, and the first label mapped to row 1 of the unary matrix.

The above minor change should fix this, ergo label 1 corresponds to row 1, the number of rows is equal to M, labels go from 1 to M.