Improved fast parallel thinning algorithm for contours

The problem of thinning contours obtained via segmentation is discussed to reduce the quantity of data processing and prepare for the pre-processing of vectorization. An improved fast parallel thinning algorithm is therefore proposed to the contours in military maps. Two-step thinning algorithm is adopted to process the contour thinning. Some restrictive conditions are added to the existing logistic rules, thus enabling the algorithm to deal with the symmetry problem of module board with the deleting look-up table given to improve the operation speed of the algorithm. The simulation result shows that there is no distorted skeleton and excessive corrosion and the connectedness is satisfactory. The proposed algorithm is proved ideal to deal with contour thinning.