An Efficient Quick Thinning Algorithm

A new thinning algorithm is addressed in this paper. The most important feature in this paper is that it thins symbols to their central lines with high speed. This means that the method is rotation invariant. Compared to the method of Ahmed and Ward, it can improve the speed and solve their falls on two-pixel wide lines. The method in this paper contains two steps. The first one uses the concept of weight-value to separate the rules into 6 groups in order to improve the speed of thinning; The second one uses 2 rules to make sure that the skeleton is single pixel and can preserve the connectivity. The results show that this method has good effect on preserving the topology of symbols and letters.