This method includes two steps: surface fitting based on fairing constraint and adding offset to form the threshold surface.
这种方法首先对背景进行光顺限制的曲面拟合，再通过设置一个偏移量来形成阈值曲面。
2
For suboptimal method based on optimal threshold analysis, a recursive form of threshold selection using Newton iteration is developed with false alarm probability constraint.