translate

The translate command can be used for simple conversion of files based on their file extensions. It can also be used for constructing pipelines directly from the command-line.

$ pdal translate [options] input output [filter]
--input, -i        Input filename
--output, -o       Output filename
--filter, -f       Filter type
--json             JSON array of filters
--pipeline, -p     Pipeline output
--metadata, -m     Dump metadata output to the specified file
--reader, -r       Reader type
--writer, -w       Writer type

The --input and --output file names are required options.

The --pipeline file name is optional. If given, the pipeline constructed from the command-line arguments will be written to disk for reuse in the pipeline.

The --json flag can use used to specify a JSON array of filters as if they were being specified in a pipeline. If a filename follows the flag, the file is opened and it is assumed that the file contains a valid JSON array of filter specifications. If the flag value is not a filename, the value is taken to be a literal JSON string that is the array of filters. The flag can’t be used if filters are listed on the command line or explicitly with the --filter option.

The --filter flag is optional. It is used to specify drivers used to filter the data. --filter accepts multiple arguments if provided, thus constructing a multi-stage filtering operation. Filters can’t be specified using this method and with the --json flag.

The --metadata flag accepts a filename for the output of metadata associated with the execution of the translate operation.

If no --reader or --writer type are given, PDAL will attempt to infer the correct drivers from the input and output file name extensions respectively.

Example 1:

The translate command can be augmented by specifying full-path options at the command-line invocation. For example, the following invocation will translate 1.2-with-color.las to output.laz while doing the following:

  • Setting the creation day of year to 42
  • Setting the creation year to 2014
  • Setting the LAS point format to 1
  • Cropping the file with the given polygon
$ pdal translate \
    --writers.las.creation_doy="42" \
    --writers.las.creation_year="2014" \
    --writers.las.format="1" \
    --filters.crop.polygon="POLYGON ((636889.412951239268295 851528.512293258565478 422.7001953125,636899.14233423944097 851475.000686757150106 422.4697265625,636899.14233423944097 851475.000686757150106 422.4697265625,636928.33048324030824 851494.459452757611871 422.5400390625,636928.33048324030824 851494.459452757611871 422.5400390625,636928.33048324030824 851494.459452757611871 422.5400390625,636976.977398241520859 851513.918218758190051 424.150390625,636976.977398241520859 851513.918218758190051 424.150390625,637069.406536744092591 851475.000686757150106 438.7099609375,637132.647526245797053 851445.812537756282836 425.9501953125,637132.647526245797053 851445.812537756282836 425.9501953125,637336.964569251285866 851411.759697255445644 425.8203125,637336.964569251285866 851411.759697255445644 425.8203125,637473.175931254867464 851158.795739248627797 435.6298828125,637589.928527257987298 850711.244121236610226 420.509765625,637244.535430748714134 850511.791769731207751 420.7998046875,636758.066280735656619 850667.461897735483944 434.609375,636539.155163229792379 851056.63721774588339 422.6396484375,636889.412951239268295 851528.512293258565478 422.7001953125))" \
    ./test/data/1.2-with-color.las \
    output.laz \
    filters.crop

Example 2:

Given these tools, we can now construct a custom pipeline on-the-fly. The example below uses a simple LAS reader and writer, but stages a PCL-based voxel grid filter, followed by the PMF filter. We can even set stage-specific parameters as shown.

$ pdal translate input.las output.las pclblock pmf \
    --filters.pclblock.json="{\"pipeline\":{\"filters\":[{\"name\":\"VoxelGrid\"}]}}" \
    --filters.pmf.approximate=true --filters.pmf.extract=true

Example 3:

This command reads the input text file “myfile” and writes an output LAS file “output.las”, processing the data through the stats filter. The metadata output (including the output from the stats filter) is written to the file “meta.json”.

$ pdal translate myfile output.las --metadata=meta.json -r readers.text \
    --json="[ { \"type\":\"filters.stats\" } ]"