Validity and regression tests for UFO.

Get the input data by running

./setup.sh

Execute

./run.py

and all test scripts will be run and evaluated. The output contains success state as well as the sum of absolute difference to the expected reference output.

1. Think of a name for the test, for example threshold.
2. Compute the expected reference, call it threshold-ref.tif and place it into the reference/ dir.
3. Add an entry to tests.json.
4. Profit.