An Algorithm for Turning Points´ Row Permutation of Image Boundary into Sequence Permutation

Image output by computer is done row by row, with which we cannot know the topological relations between points at image boundary. To obtain the closed boundary of the target from an image and turn points´ row permutation of boundary into sequence permutation, an algorithm based on 4-connection relation of pixel points is proposed and analysis of correctness and complexity is given. Compared with classical operators and literature method, the single pixel boundary extracted from an image by this algorithm is more whole and more distinct. Moreover, it has lower time complexity. The obtained sequence permutation of points is also conducive to follow-up image processing.