A simple LiDAR thinning algorithm for LAS/LAZ/ASCII. It places a uniform grid over the points and within each grid cell keeps only the point with the lowest (or ‘-highest’) Z coordinate a -random’ point per cell or the most ‘-central’ one. When keeping ‘-random’ points you can in addition specify a ‘-seed 232’ for the random generator. Instead of removing the thinned out points from the output file you can also flag them with ‘-flag_as_withheld’ or ‘-flag_as_keypoint’. Then you can use the standard ‘-drop_withheld’ or ‘-keep_withheld’ filters to get either the thinned points or their complement. For more details see the README file.