Question

I have a volume (3D matrix) that has undergone a segmentation process. Most of the volume consist of NaNs (or zeros), except regions that have passed some criteria (see picture). I need to know how large each remaining segment is in number of voxels and how is their distribution on the 2D planes (xy, xz, yz). Is there anything in matlab that can help me do this in an efficient way rather than direct search? The volume can be rather large. For ex. in the attached picture there is one segment in yellowish/brownish colour of 7 voxels and extends more vertically than in xy.
Thanks in advance.

Answer 1

The most convenient solution is to use REGIONPROPS. In your example:

stats = regionprops(image, 'area', 'centroid')

For every feature, there is an entry in the structure stats with the area (i.e. # of voxels) and the centroid.