Computation of features of 2-D polycurve-encoded boundaries

Polycurve codes is the name of a line-drawing model for describing object boundaries and contour lines. It belongs to chain-coding families such as chain codes and generalized chain codes. Polycurve codes make possible the direct extraction and labeling of predefined high-level line and arc segments from irregular object boundaries. Several algorithms for computing features of the objects from polycurve-encoded boundaries are presented. Some geometric calculation such as inverse and intersection points of two polycurves are also considered. The algorithms use look-up tables indexed by segment labels so that only elementary operations such as addition and subtraction may be required