Estimation of discrete curvature based on chain-code pairing and digital straightness

Estimation of discrete curvature is a challenging problem, since a mere replacement of functional derivatives by numerical differences fails to produce the desired result. Several algorithms have been proposed so far, which are mostly based on the concepts of real geometry and hence are computationally expensive. The existing measure of k-curvature, though easy to compute, is crippled with some unwanted syndromes arising out of improper consideration of chain codes. Hence, an improved algorithm for estimating k-curvature is proposed, which is marked by its inherent simplicity and computational attractiveness, and produces the expected estimate, whether the concerned point has an extreme (high or low) curvature or the concerned segment has a constant or changing curvature. Examples and experimental results demonstrate the fitness and effectiveness of the proposed technique for digital curves of arbitrary shapes.