图像匹配模型xfeat的C++版本

代码主要来自https://github.com/verlab/accelerated_features/issues/9，该博客主要介绍环境配置过程

1 配置onnxruntime

从https://github.com/Microsoft/onnxruntime/releases/tag/v1.10.0中下载已经编译好的onnxruntime-linux-x64-gpu-1.10.0

2 配置opencv

2.1 从https://opencv.org/blog/opencv-4-5-2/中下载源码

2.2 解压opencv源码包

unzip opencv-4.5.2

2.3 在解压的目录下，创建build文件夹，并进入

mkdir build
cd build

2.4 在build文件夹的内部执行如下命令

cmake -D CMAKE_BUILD_TYPE=Release -D CMAKE_INSTALL_PREFIX=/usr/local ..

2.5 执行make命令，进行编译

sudo make

3 下载源码和权重文件

https://github.com/verlab/accelerated_features/files/15329104/xfeat.zip

#include <chrono>
#include <iostream>
#include "omp.h"
#include <opencv2/opencv.hpp>
#include <onnxruntime_cxx_api.h>

// for onnx model path
const ORTCHAR_T* stringToOrtchar_t(std::string const& s)
{
#ifdef _WIN32
	const char* CStr = s.c_str();
	size_t len = strlen(CStr) + 1;
	size_t converted = 0;
	wchar_t* WStr;
	WStr = (wchar_t*)malloc(len * sizeof(wchar_t));
	mbstowcs_s(&converted, WStr, len, CStr, _TRUNCATE);

	return WStr;
#else
	return s.c_str();
#endif // _WIN32
}

bool initOrtSession(Ort::Env& env, Ort::Session& session, std::string& modelPath, const int& gpuId = 0)
{
	const ORTCHAR_T* ortModelPath = stringToOrtchar_t(modelPath);

	bool sessionIsAvailable = false;
	/* 
	if (sessionIsAvailable == false)
	{
		try
		{
			Ort::SessionOptions session_options;
			session_options.SetGraphOptimizationLevel(GraphOptimizationLevel::ORT_ENABLE_ALL);

			// try Tensorrt 
			OrtTensorRTProviderOptions trtOptions{};
			trtOptions.device_id = gpuId;
			trtOptions.trt_fp16_enable = 1;
			trtOptions.trt_engine_cache_enable = 1;
			trtOptions.trt_engine_cache_path = "./trt_engine_cache";


			trtOptions.trt_max_workspace_size = (size_t)4 * 1024 * 1024 * 1024;

			session_options.AppendExecutionProvider_TensorRT(trtOptions);

			session = Ort::Session(env, ortModelPath, session_options);
			
			sessionIsAvailable = true;
			std::cout << "Using accelerator: Tensorrt" << std::endl;
		}
		catch (Ort::Exception e)
		{
			std::cout << "Exception code: " << e.GetOrtErrorCode() << ", exception: " << e.what() << std::endl;
			std::cout << "Failed to init Tensorrt accelerator, Trying another accelerator..." << std::endl;
			sessionIsAvailable = false;
		}
		catch (...)
		{
			std::cout << "Failed to init Tensorrt accelerator, Trying another accelerator..." << std::endl;
			sessionIsAvailable = false;
		}
	}
	*/

	if (sessionIsAvailable == false)
	{
		try
		{
			Ort::SessionOptions session_options;
			session_options.SetGraphOptimizationLevel(GraphOptimizationLevel::ORT_ENABLE_ALL);

			OrtCUDAProviderOptions cuda0ptions;
			cuda0ptions.device_id = gpuId;
			cuda0ptions.gpu_mem_limit = 4 << 30;

			session_options.AppendExecutionProvider_CUDA(cuda0ptions);

			session = Ort::Session(env, ortModelPath, session_options);

			sessionIsAvailable = true;
			std::cout << "Using accelerator: CUDA" << std::endl;
		}
		catch (Ort::Exception e)
		{
			std::cout << &#