Reproduce the original license

Oct 13, 2025 by wbrum.org 108 views

Possible License/Copyright Chain Issues: Understanding the Complexity of Open-Source Code

Introduction

As the open-source community continues to grow, the importance of proper licensing and copyright attribution becomes increasingly crucial. In this article, we will delve into the complexities of license and copyright chain issues, using the JBIG2 decoder as a case study. We will explore the discrepancies found in the licensing and copyright of this code, and discuss the implications of these issues.

The JBIG2 Decoder: A Permissive License

The JBIG2 decoder is a software library that allows developers to decode and manipulate JBIG2 images. The library is available under permissive licenses, making it an attractive option for developers who want to use the code in their projects. However, as we will see, the licensing and copyright of the code are not as straightforward as they seem.

The Original Code: JPedal Java Implementation

The JBIG2 decoder is based on the JPedal Java implementation, which is licensed under the BSD-3-Clause license. The BSD-3-Clause license is a permissive license that allows developers to use, modify, and distribute the code freely. However, when the code was ported to C#, the license was changed to the MIT license, which is also permissive but has some differences from the BSD-3-Clause license.

License Discrepancies: A Case Study

A recent review of the JBIG2 decoder code revealed some discrepancies in the licensing and copyright. The repository contains an MIT license file with only the copyright line of the current maintainer. However, this is not correct and should include the copyright lines from the original authors, as specified in the licenses of the JBig2Decoder.NETCore and JBig2Decoder.NET repositories.

**MIT License File: Incorrect Attribution**

The MIT license file in the repository contains only the copyright line of the current maintainer. However, this is not correct and should include the copyright lines from the original authors.

* https://github.com/winkingsoftware/JBig2Decoder.NETCore/blob/master/LICENSE
* https://github.com/Daniel-Glucksman/JBig2Decoder.NET/blob/master/LICENSE.txt

Implications of License Discrepancies

The implications of license discrepancies are significant. If the code is used in a project without proper attribution, it could lead to copyright infringement claims. Additionally, if the code is modified and distributed under a different license, it could create confusion and make it difficult for developers to understand the terms of the license.

Conclusion

In conclusion, the JBIG2 decoder is a complex piece of software with a rich history. The licensing and copyright of the code are not as straightforward as they seem, and discrepancies have been found in the repository. It is essential for developers to understand the implications of license discrepancies and to ensure that proper attribution is given to the original authors.

Recommendations

Based on the findings of this article, we recommend the following:

Update the license file: Update the MIT license file to include the copyright lines from the original authors.
Reproduce the original license: Reproduce the original BSD-3-Clause license and copyright in the C# port of the code.
Provide clear attribution: Provide clear attribution to the original authors in the code and documentation.

By following these recommendations, developers can ensure that the JBIG2 decoder is used and distributed correctly, and that the original authors are properly attributed.

Introduction

In our previous article, we explored the complexities of license and copyright chain issues in open-source code, using the JBIG2 decoder as a case study. In this article, we will answer some frequently asked questions (FAQs) about license and copyright chain issues, and provide guidance on how to navigate these complex issues.

Q: What is a license chain issue?

A: A license chain issue occurs when a piece of software is modified or distributed under a different license than the original license. This can create confusion and make it difficult for developers to understand the terms of the license.

Q: Why is it important to attribute the original authors?

A: Attributing the original authors is essential to ensure that the original creators of the code are properly recognized and credited. This is also important for maintaining the integrity of the code and preventing copyright infringement claims.

Q: What is the difference between a permissive and a restrictive license?

A: A permissive license allows developers to use, modify, and distribute the code freely, while a restrictive license imposes certain restrictions on the use and distribution of the code.

Q: Can I use a different license for my project?

A: Yes, you can use a different license for your project, but you must ensure that the new license is compatible with the original license. This is known as a "compatible license."

Q: How do I determine if a license is compatible?

A: To determine if a license is compatible, you can use a license compatibility tool or consult with a lawyer. Some popular license compatibility tools include the Open Source Initiative's (OSI) License Compatibility Tool and the SPDX License List.

Q: What are the implications of using a different license?

A: The implications of using a different license can be significant. If the new license is not compatible with the original license, it can create confusion and make it difficult for developers to understand the terms of the license. This can also lead to copyright infringement claims.

Q: How do I update the license file?

A: To update the license file, you must include the copyright lines from the original authors and reproduce the original license and copyright in the new license file.

Q: What are the best practices for managing licenses and copyrights?

A: The best practices for managing licenses and copyrights include:

Clearly attributing the original authors: Ensure that the original creators of the code are properly recognized and credited.
Using a compatible license: Use a license that is compatible with the original license.
Reproducing the original license: Reproduce the original license and copyright in the new license file.
Providing clear documentation: Provide clear documentation on the terms of the license and the copyright.

Q: What resources are available for learning more about license and copyright chain issues?

A: There are many resources available for learning more about license and copyright chain issues, including:

Open Source Initiative (OSI): The OSI provides guidance on open-source licensing and copyright issues.
Software Freedom Law Center (SFLC): The SFLC provides guidance on open-source licensing and copyright issues.
License Compatibility Tool: The License Compatibility Tool is a tool that helps developers determine if a license is compatible with the original license.

Conclusion

In conclusion, license and copyright chain issues are complex and can have significant implications for developers. By understanding the basics of license and copyright chain issues and following best practices, developers can ensure that their projects are properly licensed and attributed.