Uniform Resampling of Digitized Contours

Abstract

This paper addresses the problem of the nonuniform intersample distance of digital curves obtained as a result of quantization of continuous contours on a square lattice. A resampling algorithm based on variable-factor interpolation and decimation is presented, and its performance is evaluated analytically and by computer simulations assuming the grid-intersect quantization. It is shown that the output of the resampling algorithm outperforms the original digital curve in terms of the average and maximum error in the measurement of length by 50 and 73 percent, respectively. The resampling algorithm can be used as a preprocessing stage in shape analysis systems to enhance their performance by increasing the accuracy and consistency of both local and global features such as curvature and the Fourier shape descriptors.