活動輪廓模型在醫(yī)學圖像分割中的應用.pdf

1、The increasingly important role of medical imaging in the diagnosis and treatment of disease has opened an array of challenging problems centered on the computation of accurate geometric models of anatomic structures fro

2、m medical images. A promising approach to tackle such problems is the use of active contour models. These powerful models have proven to be effective in segmenting,visualizing, matching and tracking anatomic structures b

3、y exploiting constraints derived from the image data together with a priori knowledge about the location, size and shape of these structures. Furthermore, active contour models support highly intuitive interaction mechan

4、isms that allow medical scientists and practitioners to bring their expertise to bear on the image interpretation task. The focus of this dissertation is to investigate active contour models. An energy minimizing fo

5、rmulation is applied to get mathematical representation of an object boundary. The finite difference method is applied to do numerical implementations of the deformable model. GVF model is a kind of representative a

6、ctive contour model. It derives from generalized force balance equations, a vector diffusion equation is employed to diffuse the gradient of an edge map in regions distant from the boundary, yielding a general type of fo

7、rce field which can be decomposed in to an irrotational component and a solenoidal component. The excellence of GVF model is analyzed in this thesis.2D GVF computations are implemented using MATLAB code. In the prac

8、tice of application, the present models often subject to the influence of noises and fake edges, Based on the multi-scale image analysis, the improved gradient vector flow(GVF) including gradient direction information in