Hi all,
in r66181 I’ve added a simple decimation to v.in.lidar. It reduces number of imported points by skipping or limiting number of imported points. Here are the new options:
skip
Do not import every n-th point. For example, 5 will import 80 percent of points. If not specified, all points are imported.
preserve
Import only every n-th point. For example, 4 will import 25 percent of points. If not specified, all points are imported.
offset
Skip first n points. Skips the given number of points at the beginning.
limit
Import only n points. Imports only the given number of points.
Note that the skipping is happening after return, class, and region filters. It seems a bit slower since all these tests happen and then you skip the point anyway but on the other hand, you are selecting every n-th point from the class/return/region you actually care about.
With this kind of decimation, the points you get at the end depends on how the points are stored in the file.
Please let me know what you think.
Vaclav
https://trac.osgeo.org/grass/changeset/66181
PS: The documentation will hopefully follow.