Abstract The point clouds filtering based on scanning lines, which does not need to establish complex data structure, is not only simple in computation structure but also efficient in computation time. It is suitable for departing the terrain points and non-terrain points from the point clouds. In order to leave out the pre-processing before the filtering, a modified filtering of point clouds based on so called “pseudo scanning lines” by slope is proposed in this paper. The modified algorithm not only has the advantages of the point clouds filtering based on scanning lines, but also makes sure that the starting reference point for judging the terrain information is a real terrain point. In addition, a curve fitting method with moving window is used to follow the modified point clouds filtering in order to avoid the difference of neighboring pseudo scanning lines for the same terrain. An actual example shows that the modified point clouds filtering with the corresponding curve fitting is efficient.
