Straight line approximation and 1D representation of off-line handwritten text

摘要

Algorithms to process off-line Arabic handwriting before recognition are presented. First, an algorithm that converts smoothed and thinned images into straight line approximations is described. Second, an algorithm is developed to obtain a 1D representation of off-line Arabic handwriting. This is achieved by first finding the start-end pair of vertices of writing. Then a stroke is traversed from the start to the end vertex by solving the Chinese postman's problem for its graph. Special rules are applied to enforce temporal information on the stroke to obtain the most likely traversal that is consistent with Arabic handwriting. Finally, an algorithm is suggested to reduce straight line approximations to other approximations in which loops are represented by vertices with features. In testing, 2256 unconstrained handwritten strokes, written by six writes, were used. In 96.5% of the samples, the algorithm restored the actual temporal information.