An efficient integer-based skeletonization algorithm

Abstract

The problem of generating vector representation of a raster image has been the question of present interest for decades. Although, there are many approaches to this problem, most of them suffer from sophisticated computations and irrational memory usage. We introduce here a new skeletonization algorithm that is very efficient in terms of time and memory consumption. Starting from the description of our approach to the concept of skeleton on raster grid, we present a comprehensive explanation of the algorithm. Its main idea consists of generating a special polyline for each raster line considering them in top-to-bottom direction; skeleton is constructed from points of these polylines. The skeletons obtained by our algorithm allow the precise reconstruction of the initial raster shapes; therefore they may reflect some artifacts possible on raster grid. For this reason, we also present here two algorithms of simplification and our approach to defects filtering on a stage of skeleton generation. The time of simplification by presented algorithms depends linearly on the number of input points that makes these methods fast and efficient. The paper concludes with performance evaluation and discussion of possible implementations of the introduced techniques.