LAS .NET Library

The LAS .NET library is a comprehensive, high-performance library for reading and writing ASPRS LAS LiDAR point cloud files. It supports LAS versions 1.1-1.5 and provides a modular package structure with extensions for various formats and cloud platforms.

Features

• High Performance: Low-allocation types for efficient point cloud processing
• Multiple LAS Versions: Full support for LAS 1.1 through 1.5
• Compression: Support for LAZ compression
• Cloud Integration: Read/write from Azure Blob Storage, Amazon S3, and HTTP(S) endpoints
• Arrow Integration: Read/write to Apache Arrow format
• DataFrame Support: Integration with Polars DataFrames
• Geodesy Support: OGC WKT coordinate system support via PROJ
• Indexing: Spatial indexing for fast point access
• Tiling Support: Read tiling VLRs from LAS files
• AOT Compatible: Ready for Native AOT compilation

Packages

Package	Version	Description
Altemiq.IO.Las		Core library for reading/writing LAS files
Altemiq.IO.Las.Compression		LAZ compression support
Altemiq.IO.Las.Cloud		Cloud-Optimized Point Clouds (COPC)
Altemiq.IO.Las.Azure		Azure Blob Storage support
Altemiq.IO.Las.S3		Amazon S3 support
Altemiq.IO.Las.Http		HTTP(S) support
Altemiq.IO.Las.Indexing		Spatial indexing
Altemiq.IO.Las.Tiling		Tiling VLR support
Altemiq.IO.Las.Arrow		Apache Arrow integration
Altemiq.IO.Las.Compression.Arrow		Compressed Arrow integration
Altemiq.IO.Las.DataFrame		Polars DataFrame integration
Altemiq.IO.Las.Compression.DataFrame		Compressed DataFrame integration
Altemiq.IO.Las.Geodesy		OGC WKT coordinate systems

Command-Line Tool

The las command-line tool is available as a Native AOT-compiled executable and container. It provides a comprehensive interface for working with LAS files.

Installation

.NET Tool

dotnet tool install --global Las

Container

docker run ghcr.io/altemiq/io/las

Usage

# Show help
las --help

# Show file info
las info input.las

# Create spatial index
las index input.las

# Verify COPC file
las copc verify input.copc.laz

# Convert to LAS
las to las --input input.las --output output.las

# Convert to LAZ
las to laz --input input.las --output output.laz

# Convert to COPC (Cloud Optimized Point Cloud)
las to copc --input input.las --output output.copc.laz

# Sort points
las to sorted --input input.las --output output.las

# Split file into parts
las to exploded --input input.las --output output/

Basic Usage

Reading LAS Files

using Altemiq.IO.Las;

using LasReader reader = new("example.las");

while (await reader.ReadPointDataRecordAsync() is { PointDataRecord: not null } point)
{
    Console.WriteLine($"Point: {point.X}, {point.Y}, {point.Z}");
}

Writing LAS Files

using Altemiq.IO.Las;

HeaderBlockBuilder builder = new()
{
    SystemIdentifier = "My System",
    GeneratingSoftware = "My.Software.exe",
    Version = new(1, 1),
    PointDataFormatId = 1,
    LegacyNumberOfPointRecords = 1,
};

using LasWriter writer = new("example.las");
writer.Write(builder.HeaderBlock, geoKeyDirectoryTag, extraBytes);

Reading Compressed LAZ Files

using Altemiq.IO.Las;

using LazReader reader = new("example.laz");

while (await reader.ReadPointDataRecordAsync() is { PointDataRecord: not null } point)
{
    Console.WriteLine($"Point: {point.X}, {point.Y}, {point.Z}");
}

Cloud Integration

using Altemiq.IO.Las;
using Altemiq.IO.Las.S3;

var url = new Uri("s3://bucket/path/file.las");
LasReader reader = new(S3Las.OpenRead(url));

Arrow Integration

using Altemiq.IO.Las;

using LasReader reader = new("example.las");
var batches = reader.ToArrowBatches();

ArrowLasReader arrowReader = new(batches);

DataFrame Integration

using Altemiq.IO.Las;

using LasReader reader = new("example.las");
var data = Polars.CSharp.DataFrame.ReadLas(reader);

Building

# Restore dependencies
dotnet restore

# Build
dotnet build

# Run tests
dotnet test

# Package
dotnet pack

Requirements

• .NET 10.0 (latest)
• .NET 9.0
• .NET 8.0
• .NET 7.0
• .NET Standard 2.1
• .NET Standard 2.0

Contributing

This project welcomes contributions and suggestions. Most contributions require you to agree to a Contributor License Agreement (CLA) declaring that you have the right to, and actually do, grant us the rights to use your contribution.

License

This project is licensed under the MIT License. See the LICENSE file for details.

Acknowledgments

• ASPRS for the LAS specification
• LAStools for LAZ compression library
• Apache Arrow for the columnar format
• PROJ for coordinate system transformations

Resources

• ASPRS LAS Specification
• LAZ Specification
• Cloud Optimized Point Cloud
• GitHub Repository