Image compression algorithm for fast parallel thinning of binary images

An efficient image compression technique as a preprocessing step for skeletonisation is presented. For this purpose a 5*5 pattern window is used, in which an internal 3*3 nonoverlapping window does the compression whilst the outer ring of pixels helps to preserve the image connectivity during compression. Comparative evaluation based on experimental results, execution timings and quality of the skeleton obtained, show that this algorithm is faster and more efficient than many other existing thinning algorithms. This algorithm is also more efficient for noisy images than other thinning algorithms because it simultaneously performs median filtering operations.