How to Successfully Compile OpenCV Projects with Non-Standard .so File Locations in C+ +

Описание: Discover how to compile your OpenCV 2.4 project in C+ + when your .so files are in a non-standard directory without root access.
---
This video is based on the question https://stackoverflow.com/q/72608807/ asked by the user 'Adam Rutledge' ( https://stackoverflow.com/u/13555760/ ) and on the answer https://stackoverflow.com/a/72609287/ provided by the user 'Adam Rutledge' ( https://stackoverflow.com/u/13555760/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: Attempting to use OpenCV 2.4 C+ + library when .so files installed in a non-standard location

Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/l...
The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license.

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
Compiling OpenCV Projects with Non-Standard Library Files in C+ +

OpenCV is a powerful computer vision library that boasts a wealth of functionalities for image and video processing. However, compiling projects, especially in unique environments (like a virtual machine without root access), can sometimes be a challenge, particularly if the necessary .so files are not in the standard paths. This guide will guide you through the steps to successfully compile an OpenCV project in C+ + when the library files are located in a non-standard directory.

Understanding the Problem

Imagine you are working on a virtual machine where you don’t have administrator rights, and all your OpenCV 2.4 .so files are installed in $HOME/.local/lib. You want to include the OpenCV library in your C+ + project. However, when you try compiling using G+ + , you encounter errors about missing header files. Here are the key issues you might face:

Incorrect paths: The compiler can't find the OpenCV header files.

Linking issues: The G+ + linker cannot locate the appropriate .so files.

Environment variable settings: Your system might also need adjustments to find the linked libraries at runtime.

The Solution: Steps to Compile Your Project

Follow these steps to compile your OpenCV project correctly:

Step 1: Include the Correct Header Files

First, ensure you are including the correct OpenCV header files in your source code. For example, for a general OpenCV application, you might use:

[[See Video to Reveal this Text or Code Snippet]]

or specifically:

[[See Video to Reveal this Text or Code Snippet]]

For broader functionality across modules, use the former.

Step 2: Set Up the Compilation Command

Your compilation command should specify both the include path and the library path. Here’s how you can structure your command:

[[See Video to Reveal this Text or Code Snippet]]

Breakdown of the Command

-I$HOME/.local/include: This flag tells G+ + where to find the OpenCV header files.

-L$HOME/.local/lib: This specifies the location of the shared libraries during linking.

-l Flags: Each -lopencv_* flag links to specific components of the OpenCV library. Make sure to specify all necessary modules for your project’s functionality.

Final Output: The -o OpenCVTest option names the output executable.

Step 3: Setting the Library Path for Execution

After compiling your binary, you’ll need to ensure the system can find the libraries during runtime. You can do this by exporting the library path using the following command:

[[See Video to Reveal this Text or Code Snippet]]

Step 4: Running Your Compiled Program

Finally, after executing the export command, you can safely run your compiled program:

[[See Video to Reveal this Text or Code Snippet]]

Conclusion

Compiling an OpenCV project in C+ + on a virtual machine with libraries in a non-standard location may seem daunting at first, but by following the structured approach outlined above, you can overcome potential problems. Remember to include the appropriate header files, correctly specify your include and library paths, and set the runtime library path.

With these steps, you can focus more on developing your OpenCV applications and less on debugging compilation issues. Happy coding!