关键词: 图像分割, CAD系统, 肺部CT, 自动阈值, 分水岭分割

Abstract: This paper puts forward the base frame of lung segmentation first.Using optimal thresholding and mathematical morphologic methods，the rough image of lung is acquired.Then，we present a fast adaptive segmentation refinement algorithm，aiming at the unsuccessful left and right segmentation of thredsholding.Experiments on clinical 3D pulmonary images show the algorithm’s result is very close to the expert manual outlines，and it is very effective for the separation of left and right lung with a successful segmentation ratio 94.8%.

Key words: image segmentation, CAD system, pulmonary CT, automated thresholding, watershed segmentation