LCCP/CPC Segmentation and Supervoxel indexing

Hi there,

while testing segmentation with LCCP and the recent CPC, I always observe some out-of-order small blobs in the middle of larger segments, which are not tackled by mergeSmallSegment.
I've done some debugging and found that those points are in the octree leaf with voxel_data.owner_ == 0 (see getLabeledCloud in supervoxel_clustering.cpp), have label 0 and are not in the adjacency graph, because the list of SupervoxelHelper is initialised with the label beginning with 1 (see createSupervoxelHelpers):

supervoxel_helpers_.push_back (new SupervoxelHelper(i+1,this));

So, I assume this is not a desired behaviour, though I don't quite get why the indexing skips 0.

Kind regards,
Nikita

Start in supervoxel_clustering.cpp, tracing getLabeledCloud and createSupervoxelHelpers, especially the SupervoxelHelper indexing and owner_ == 0 points. Reproduce the reported LCCP/CPC segmentation case and follow how label-0 leaves bypass the adjacency graph and mergeSmallSegment. Done means the out-of-order small blobs are handled consistently with larger segments and the intended indexing behavior is established.