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’ or ‘-random’) Z coordinate. 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 mark them as ‘-withheld’. The 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.