openvino/docs/IE_DG/Extensibility_DG/Extension.md

Extension Library

Inference Engine provides an InferenceEngine::IExtension interface, which defines the interface for Inference Engine Extension libraries. Inherit all extension libraries from this interface. The example below contains an implementation of two operations: Template used as an example in this document and FFT used as a more complex example from the Custom Operations Guide.

Note

: FFT operation is implemented using the OpenCV library functions cv::dft and cv::idft.

Based on that, the declaration of an extension class can look as follows:

@snippet template_extension/extension.hpp extension:header

The extension library should contain and export the InferenceEngine::CreateExtension method, which creates an Extension class:

@snippet template_extension/extension.cpp extension:CreateExtension

Also, an Extension object should implement the following methods:

• InferenceEngine::IExtension::Release deletes an extension object.

• InferenceEngine::IExtension::GetVersion returns information about the version of the library.

@snippet template_extension/extension.cpp extension:GetVersion

Implement the InferenceEngine::IExtension::getOpSets method if the extension contains custom layers. Read Custom nGraph Operation for more information.

To understand how to integrate execution kernels to the extension library, read the documentation about development of custom CPU kernels.

To understand how to register custom ONNX operator to the extension library, read the documentation about custom ONNX operators.