用一个重正化函数F z F bz /a 作为支气管结构第z 个层次 的半径则参数b 表征了对半径变化有贡献的标度区间的测度而a 表 示某个特征标度的权重-with an emphasis of function F is F bz z / bronchial structure as a first level of z radius parameter b is characterized by changes in the radius can contribute to the s

针对复杂背景及目标的分形特性差异, 提取图像四个方向的灰度梯度, 选择最小梯度大于阈值的区域进行平滑滤波, 最后对分维参数进行分段线性拉伸-Extraction of image in four directions of the gray gradient, minimum gradient is greater than the threshold area smoothing filter, the last on the fractal dimension parameters of p