Contour detection: unexpected results outside ROI

[PierreRaybaut]

In DataLab, the "Computing > Contour detection" feature is based on scikit-image skimage.measure.find_contours as described in this tutorial.

When performing a contour detection on a ROI (which is a NumPy masked array in DataLab's model), some results still appear outside the ROI and should be ignored:

This issue is related to Issue #32.

[PierreRaybaut]

Now, thanks a workaround, the erroneous contours are filtered out.

A new test module cdl.tests.features.images.contour_fabryperot_app has been added to test the contour detection feature on a Fabry-Perot image (thanks to @emarin2642 for the contribution)

[PierreRaybaut]

I've just opened an issue on scikit-image GitHub project, in case it's relevant:
scikit-image/scikit-image#7300