tailieunhanh - COMPUTER-AIDED INTELLIGENT RECOGNITION TECHNIQUES AND APPLICATIONS phần 9

trong đó chúng tôi đang cố gắng xây dựng một kỹ thuật khai thác dữ liệu dựa trên các luật kết hợp chiết xuất từ phương pháp DFC của chúng tôi để chụp hình quang tuyến vú phân loại. Chúng tôi cũng đang có ý định, mục đích của phân loại chụp hình vú, | Topological Segmentation 395 junction voxels q and r are transformed into nodes and the remaining candidate s is then identified as another junction in a new sequential visit of the candidate junction set likely yielding an undesirable skeleton model. To overcome this deficiency we propose a global approach for the resolution of thick junctions 1. Re-sort the candidate junction set Sc Pi i 1 . n in a descending order by the value of f26b of each voxel in Sc such that fv 6b pi fv6b pi 1 for i 1 . . . n 1. 2. Sequentially visit each voxel p in Sc and a set p as a junction b transform all junction candidates in Ne26 p n Sc to nodes and c update candidate voxel set Sc Sc Sc N26 p n Sc. Branch Formation After all skeleton voxels are classified the raw skeleton is ready for the formation of branches. Here we introduce two additional values associated with a skeleton voxel Definition f p is the number of branches containing a skeleton voxel p. If p is a tip or node then f p 1. If p is a junction then f l p f26b p . Definition f s p indicates the number of times a voxel p has been visited in the skeleton segmentation process. Assuming each skeleton voxel p is visited only once in the formation of each single branch containing voxel p we call p unsaturated if f s p f1 p or saturated if fs p f1 p . all branches containing p have been determined . Let Su be the set consisting of all unsaturated skeleton voxels and voxel p f1 p n f s p m and m n be an end in Su. We build the m n undetermined branches containing p with the following branch formation procedure 1. Identify a voxel set E which consists of all unsaturated skeleton voxels within N26 p E Su n N26 p . 2. Form a branch L which contains an unsaturated skeleton voxel e e e E and e p a Increase fs e and fs p by one. b If e is an end build the branch L simply with voxels p and e L p e Figure a . c If e is a node then perform a 26-scan over the voxel set Su with the voxel e as the initial scanning front to .