Subset a LAS/LAZ by a set of polygons

subset_las.sh

#! /bin/bash

# Crop a LAS file by multiple polygons. Implemented for lastools.
# example:
#   subset_las.sh <path to LAS file> <path to polygons directory>

LAS_IN=$1
DIR=$2

for f in $(dir $DIR)
do
  file=$DIR/$f
  filename=$(basename "$file")
  las_out="${filename%.*}".laz
  re_lead='(?<=Extent: \()'
  re_float='[0-9]{6}[.][0-9]{6}'
  min_x="$(ogrinfo -so -al $file | grep -P -o "$re_lead""$re_float")"
  re_lead="(?<=Extent: \("$re_float", )"
  min_y="$(ogrinfo -so -al $file | grep -P -o "$re_lead""$re_float")"
  re_lead="(?<=Extent: \("$re_float", "$re_float"\) - \()"
  max_x="$(ogrinfo -so -al $file | grep -P -o "$re_lead""$re_float")"
  re_lead="(?<=Extent: \("$re_float", "$re_float"\) - \("$re_float", )"
  max_y="$(ogrinfo -so -al $file | grep -P -o "$re_lead""$re_float")"

  echo "Saving $las_out"
  las2las -i $LAS_IN -keep_xy $min_x $min_y $max_x $max_y -keep_every_nth 5 -cores 4 -o $(pwd)/$las_out
done