New line-based thinning algorithm

Thinning algorithms can be classified into two general types: sequential and parallel. Most of them peel off the boundaries until the objects have been reduced to thin lines. The process is performed iteratively, the number of iterations being approximately equal to half the maximum line width of the object. Several sequential boundary based algorithms have been proposed, but they have limitations. A new line-based algorithm is presented. The thinning element of the algorithm is a line and not, as more common, a point. The algorithm is based on a new line thinning model and is applicable to objects of general shape. The line-based thinning algorithm gives the freedom of choosing the deletion width at each iteration, and thus significantly reduces the number of iterations. The selection of the deletion width is a trade-off between speed and quality of skeletons. Experimental results are used to compare this new algorithm to other sequential algorithms and their relative performances are assessed. The new algorithm is shown to be computationally more efficient.