openpose/doc/library_add_new_module.md

OpenPose Library - Steps to Add a New Module

Developping Steps

In order to add a new module, these are the recommended steps in order to develop it:

1. Create a folder with its name in the experimental/ module, e.g., experimental/hair/.
2. Implement all the functionality in one Worker. I.e., inherit from Worker and implement all the functionality on that class (copy the examples from any Worker subclass).
   1. The first letter of the class name should be W (e.g., WHairExtractor).
   2. To initially simplify development:
      1. Optionally (higher debug info), you might initially create the Worker as a non-templated class, assuming it uses std::shared_ptr<std::vector<std::shared_ptrop::Datum>> instead of directly using a template class (following the examples/tutorial_api_cpp synchronous examples). While developing, templates provide more confusing debugging info. Turn the class into a template after being initially developed.
      2. Optionally (for development speed), use op::Datum as unique argument of your auxiliary functions within that worker.
      3. Use the OpenPose Wrapper class in ThreadManagerMode::SingleThread mode (e.g., it allows you to directly use cv::imshow).
      4. If you are using your own custom Caffe -> initially change the Caffe for your version. It should directly work.
   3. Copy the design from pose/WPoseExtractor.
3. To test it:
   1. Add the functionality to Wrapper, use the experimental namespace for the new Struct (e.g., experimental::HairStruct) that the Wrapper will use. Do not change any function name from Wrapper, just add a new configure, with the new HairStruct or modify the existing ones without changing their names.
   2. Add a demo (e.g., examples/openpose/rthair.cpp) to test it.
4. Split the Worker into as many Workers as required.
5. If the Workers need extra data from Datum, simply add into Datum the new variables required (without removing/modifying any previous variables!).
6. Read also the release steps before starting this developping phase.

Release Steps

After the code is running and ready to be merged, in order to officially release the new module:

1. Move the functionality of each Worker class to the non-template class (e.g., WHairExtractor to HairExtractor). WHairExtractor will simply wrap HairExtractor. This will reduce compiling time for the user. See examples from other modules.
2. If you are using a custom Caffe version, move the custom code into the OpenPose library and change back Caffe to the default (most updated) version.
3. Move the module from experimental/hair/ to hair/.
4. Remove experimental namespaces (e.g., from Wrapper and Hair) and turn Workers into template classes.
5. Integrate the new flags to the OpenPose Demo in examples/openpose/ and optionally add some tutorial examples in examples/tutorial_api_cpp.