Extension methods are a powerful way to enhance existing libraries without modifying their source code. But did you know you can extend even closed-source commercial libraries? This technique is especially useful in computer vision applications, such as when working with the commercial library Halcon.
Extending Halcon’s HImage Class
Halcon’s HImage class allows reading, creating, and manipulating images, as well as extracting features. While Halcon provides a rich set of computer vision tools, certain tasks—like custom exposure analysis—may require additional functionality. For example, it can be helpful to calculate the number of overexposed pixels in an image. By creating an extension method, this functionality can appear directly in IntelliSense, making your workflow smoother and faster.
How to Implement an Extension Method
- Use the this keyword before the first parameter.
- The method must be static, and it must reside in a static class.
After implementing the method, it can be called directly on any HImage object, just like a native method.
Why This Matters
- Custom functionality without altering commercial library DLLs
- Seamless integration in your code with IntelliSense support
- Faster development for specialized computer vision tasks, such as overexposure analysis or image preprocessing
Learn More
For a deep dive into extension methods in C#, check out the free preview of Jon Skeet’s book C# in Depth.
Need help extending your computer vision libraries for custom automation?
Contact Subpixel at info@subpixel.hr to discuss how we can help you implement advanced features in Halcon or other libraries.
