Computation of the φ-Descriptor in the Case of 2D Vector Objects

The spatial relations between objects, a part of everyday speech, are capable of being described within an image via a Relative Position Descriptor (RPD). The phi-descriptor, a recently introduced RPD, encapsulates more spatial information than other popular descriptors. However, only algorithms for determining the phi-descriptor of raster objects exist currently. In this paper, the first algorithm for the computation of the phi-descriptor in the case of 2D vector objects is introduced. The approach used is based on the concept of Points of Interest (which are points on the boundaries of the objects where elementary spatial relations change) and dividing the objects into regions according to their corresponding relationships. The capabilities of the algorithm have been tested and verified against an existing phi-descriptor algorithm for raster objects. The new algorithm is intended to show the versatility of the phi-descriptor.