METHOD OF DEFECT EDGE RECONSTRUCTION

 BASED ON REGION GROWING ALGORITHM

AND THE HAUSDORFF DISTANCE

LUO Aimin  YIN Guofu  WEI Wanying  YIN Ying

(School of Manufacturing Science & Engineering, Sichuan University, Chengdu 610065 )

Abstract: Aiming to edge deformation in extracting the defects of X-ray weld images, a method of defect edge reconstruction based on region growing and the Hausdorff distance is proposed. Firstly, the complement of the image is computed and the size of structure is chosen by watershed algorithm. Then, the image is filtered by improved adaptive morphology filter and its two valued image comprised of the defects is obtained. On this basis, the seeds are obtained by shrinking the objects to points. The original gray value of seeds serve as the beginning value and the object region grows by combining these selected pixels whose gray values are greater than or equal to the beginning value which is renewed by 2 subtracted from the previous. Then, the object region grows iteratively and the Hausdorff distance of the Canny edge image of objects and the original objects are calculated each time. The region growing stop when the minimum Hausdorff distance is achieved. When all objects region growing are completed, the defect edge is reconstructed by region growing. The method is verified by experiments and the results prove that the method is avail to renew the original shape of defect and obtain good results in defect edge reconstruction.

Key words: Mathematical morphology filtering Hausdorff distance Region growing Edge reconstruction

CLC No: TG44

国家自然科学基金(50275100)和四川大学青年基金(JS校200323)资助项目. Received 20060510, received in revised form 20061227