I am new for handling lidar data. Actually I am using laspy for read and write laz file. I am using following syntax for writing LAZ file. It is created LAZ file on specified folder path but it took more size comparing with the input LAZ (Ex: input laz 50 mb , Output LAZ 450 mb ).

How do I resolve this?

        out_file = laspy.file.File(output_File, mode = "w", header=in_file.header)
        out_file.points = point_records

2 Answers 2


https://github.com/grantbrown/laspy says

Laspy is a pythonic library for reading, modifying and writing LAS files. Support for LAZ is limited to reading LAS version 1.0-1.3 files.

laspy does not have support for writing files in the LAZ format.


I strongly recommend PDAL for such DTM file handling and processing. I am not sure laspy directly supports compressed LIDAR format or requires extra plugin, but with PDAL you can convert between many formats, apply filters like minimum/maximum elevation, reproject etc.

Below is a small example.

import pdal
import json
pdal_pipeline = {
        "pipeline": [   
              "filename": "merged_reprojected.laz"
pipeline = pdal.Pipeline(json.dumps(pdal_pipeline))
  • This is a nice gesture but the question is explicitely about laspy. Answers with different tools are bad for anyone who comes here looking for laspy-specific answers and leave frustrated. Dec 31, 2020 at 9:21
  • I don't agree with you. Many people come here to find solutions to their problems and sometimes it is difficult or not possible to find those within the environment they ask.
    – Deniz
    Jan 1, 2021 at 20:05
  • In that case they should ask a new, open question. It is very frustrating to have a very clear problem, finding a result and then only seeing answers that suggest "hey, do something else instead". Sorry for being so negative, please don't let me discourage you! Jan 1, 2021 at 20:12

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.