| Abstract |
In this paper, we consider 3D-shape descriptors generated
by using functions on a sphere. The descriptors are
engaged for retrieving polygonal mesh models. Invariance
of descriptors with respect to rotation of a model can be
achieved either by using the Principle Component
Analysis (PCA) or defining features in which the
invariance exists. The contribution of the paper is twofold:
firstly, we define a new rotation invariant feature vector
based on functions on concentric spheres, that outperforms
a recently proposed descriptor; secondly, we compare the
two approaches for achieving rotation invariance as well
as options to use a single function or several functions on
concentric spheres to generate feature vectors.
We conclude that descriptors, which use the PCA,
outperform others, while capturing the internal structure
of a 3D-model with functions on concentric spheres can
improve retrieval effectiveness. |