CharLS .NET is a C# JPEG-LS library implementation.
JPEG-LS (ISO-14495-1) is a lossless/near-lossless compression standard for continuous-tone images.
- .NET 8.0 class library.
- Support for the .NET platforms: Windows, Linux and macOS.
A couple of benchmarks have been executed to assist to decide which codec to use. The following codecs were measured:
| Codec | Version | Release date | Description |
|---|---|---|---|
| CharLS.Managed | 0.8.0 | 2024-08-23 | C# implementation |
| CharLS.Native | 3.2.0 | 2023-09-24 | C# wrapper around C++ implementation |
| cscharls | 0.1.1 | 2017-04-24 | C# implementation |
| charls-js | 2.1.1 | 2021-10-07 | WebAssembly implementation based on C++ source |
and the following test images were used:
| Image name | Width | Height | Bits per sample | Components | Description |
|---|---|---|---|---|---|
| Tulips | 512 | 512 | 8 | 1 | Monochrome image of tulips |
| MG1 | 3064 | 4664 | 12 | 1 | Monochrome medical image |
| Delta E | 3072 | 2048 | 8 | 3 | Artificial RGB image |
The benchmarks were performed on 2 hardware platforms: x86 and ARM64.
The column 'NEAR' defines the allowed error, 0 means lossless encoding.
The column 'ILV' defines the interleave mode used to encode the image.
Characteristics of the test environment: AMD Ryzen 9 5950X, .NET 8.0.8 (X64 RyuJIT AVX2)
WebAssembly engine: Chrome V8 12.8.374.21
| Operation | NEAR | ILV | CharLS.Managed | CharLS.Native | cscharls | charls-js |
|---|---|---|---|---|---|---|
| Decode Tulips | 0 | None | 5.0 ms | 3.6 ms | 10.4 ms | 5.6 ms |
| Decode MG1 | 0 | None | 292.3 ms | 205.0 ms | 676.3 ms | 335.2 ms |
| Decode Delta E | 0 | Sample | 80.0 ms | 89.4 ms | - | 89.5 ms |
| Encode Tulips | 0 | None | 7.1 ms | 4.7 ms | 11.8 ms | - |
| Encode MG1 | 0 | None | 404.3 ms | 256.3 ms | 695.8 ms | - |
Characteristics of the test environment: Snapdragon Compute Platform, .NET 8.0.8 (Arm64 RyuJIT AdvSIMD)
WebAssembly engine: Chrome V8 12.8.374.21
| Operation | NEAR | ILV | CharLS.Managed | CharLS.Native | cscharls | charls-js |
|---|---|---|---|---|---|---|
| Decode Tulips | 0 | None | 7.2 ms | 4.7 ms | 14.3 ms | 10.5 ms |
| Decode MG1 | 0 | None | 431.7 ms | 261.8 ms | 1019.4 ms | 542.1 ms |
| Encode Tulips | 0 | None | 9.6 ms | 5.5 ms | 15.7 ms | - |
| Encode MG1 | 0 | None | 564.0 ms | 318.6 ms | 1017.2 ms | - |
CharLS.Managed can be added to your C# project using the dotnet command line or the NuGet Package Manager in Visual Studio.
dotnet add package CharLS.ManagedA sample application is included in the GitHub repository that demonstrates how to convert common image types like .bmp, .png and .jpg to .jls (JPEG-LS).
- Use Git to get a clone of this repository:
git clone https://github.com/team-charls/charls-dotnet.git- Use the .NET 8.0 CLI or Visual Studio 2022 (v17.11 or newer) to build the solution file CharLSDotNet.sln.
For example:dotnet build && dotnet test && dotnet publishto build the NuGet package.
Building can be done on all supported .NET SDK platforms: Windows, Linux or macOS
Building the NuGet package with a signed assembly DLL and NuGet package can only be done
on the Window platform with Visual Studio 2022 or with Build tools for Visual Studio 2022.
To support code signing with a code signing certificate, stored on a smart card, a
Windows command file is available: create-signed-nuget-package.cmd.
Instructions:
- Open a Visual Studio Developer Command Prompt
- Go the root of the cloned repository
- Ensure the code signing certificate is available
- Execute the command
create-signed-nuget-package.cmd certificate-thumb-print time-stamp-url
The certificate thumbprint and time stamp URL arguments are depending on the used code signing certificate.
All assembly DLLs and the NuGet package itself will be signed.
More information about JPEG-LS can be found in the README from the C++ CharLS project.