将标记分水岭分割算法用于肺癌诊断，对肺部CT图像进行平滑滤波处理后再进行梯度运算，进行分水岭算法分割，极具实用价值-t will mark the watershed segmentation algorithm for diagnosis of lung cancer, lung CT image smoothing filter processing operation after gradient, watershed segmentation algorithm, very practi