Propagate segmentation along time and slices

[espakm]

The segmentation interpolation is a very nice feature to create segmentation for intermediate slices, but it works only for 3D images, and needs to create a segment manually at least on two slices.

For 3D+t images it would be nice to propagate a segmentation along time, since the segments will probably be more or less at the same place at every timestep. (If not, the result could be manually corrected.)

The propagation can be useful also along slices. If the slices are not to far from each other, it can give a good guess that could be corrected manually.

The GUI:
Below the "apply..." and "...for all slices" buttons:

Propagate along slices: ctkRangeWidget
Propagate along time: ctkRangeWidget

The first should appear only for 3D and 3D+t images.
The second should appear only for 3D+t images.

I need this feature to analyze the image based on the segments, e.g. to plot the intensity profile of a segment along time.

[espakm]

Propagating along slices is not important, the interpolation (especially with the latest improvements) gives a more flexible and robust solution.