与OpenCV联合编译

cmake_minimum_required(VERSION 3.12 FATAL_ERROR)
project(simnet)

find_package(Torch REQUIRED)        # 查找libtorch
find_package(OpenCV REQUIRED)       # 查找OpenCV

if(NOT Torch_FOUND)
    message(FATAL_ERROR "Pytorch Not Found!")
endif(NOT Torch_FOUND)

message(STATUS "Pytorch status:")
message(STATUS "    libraries: ${TORCH_LIBRARIES}")

message(STATUS "OpenCV library status:")
message(STATUS "    version: ${OpenCV_VERSION}")
message(STATUS "    libraries: ${OpenCV_LIBS}")
message(STATUS "    include path: ${OpenCV_INCLUDE_DIRS}")

add_executable(simnet test.cpp)
target_link_libraries(simnet ${TORCH_LIBRARIES} ${OpenCV_LIBS}) 
set_property(TARGET simnet PROPERTY CXX_STANDARD 11)

-- Caffe2: CUDA detected: 9.2
-- Caffe2: CUDA nvcc is: /usr/local/cuda/bin/nvcc
-- Caffe2: CUDA toolkit directory: /usr/local/cuda
-- Caffe2: Header version is: 9.2
-- Found cuDNN: v7.4.1  (include: /usr/local/cuda/include, library: /usr/local/cuda/lib64/libcudnn.so)
-- Autodetected CUDA architecture(s): 6.1;6.1
-- Added CUDA NVCC flags for: -gencode;arch=compute_61,code=sm_61
-- Pytorch status:
--     libraries: torch;caffe2_library;caffe2_gpu_library;/usr/lib/x86_64-linux-gnu/libcuda.so;/usr/local/cuda/lib64/libnvrtc.so;/usr/local/cuda/lib64/libnvToolsExt.so;/usr/local/cuda/lib64/libcudart_static.a;-lpthread;dl;/usr/lib/x86_64-linux-gnu/librt.so
-- OpenCV library status:
--     version: 4.0.0
--     libraries: opencv_calib3d;opencv_core;opencv_dnn;opencv_features2d;opencv_flann;opencv_gapi;opencv_highgui;opencv_imgcodecs;opencv_imgproc;opencv_ml;opencv_objdetect;opencv_photo;opencv_stitching;opencv_video;opencv_videoio
--     include path: /usr/local/include/opencv4
-- Configuring done
-- Generating done
-- Build files have been written to: /home/prototype/CLionProjects/simnet/cmake-build-release

#include <opencv2/opencv.hpp>
#include "torch/script.h"
#include "torch/torch.h"

#include <iostream>
#include <memory>

using namespace std;

// resize并保持图像比例不变
cv::Mat resize_with_ratio(cv::Mat& img)   
{
    cv::Mat temImage;
    int w = img.cols;
    int h = img.rows;

    float t = 1.;
    float len = t * std::max(w, h);
    int dst_w = 224, dst_h = 224;
    cv::Mat image = cv::Mat(cv::Size(dst_w, dst_h), CV_8UC3, cv::Scalar(128,128,128));
    cv::Mat imageROI;
    if(len==w)
    {
        float ratio = (float)h/(float)w;
        cv::resize(img,temImage,cv::Size(224,224*ratio),0,0,cv::INTER_LINEAR);
        imageROI = image(cv::Rect(0, ((dst_h-224*ratio)/2), temImage.cols, temImage.rows));
        temImage.copyTo(imageROI);
    }
    else
    {
        float ratio = (float)w/(float)h;
        cv::resize(img,temImage,cv::Size(224*ratio,224),0,0,cv::INTER_LINEAR);
        imageROI = image(cv::Rect(((dst_w-224*ratio)/2), 0, temImage.cols, temImage.rows));
        temImage.copyTo(imageROI);
    }

    return image;
}


int main(int argc, const char* argv[])
{
    if (argc != 2) {
        std::cerr << "usage: example-app <path-to-exported-script-module>\n";
        return -1;
    }

    cv::VideoCapture stream(0);
    cv::namedWindow("Gesture Detect", cv::WINDOW_AUTOSIZE);

    std::shared_ptr<torch::jit::script::Module> module = torch::jit::load(argv[1]);
    module->to(at::kCUDA);

    cv::Mat frame;
    cv::Mat image;
    cv::Mat input;

    while(1)
    {
        stream>>frame;
        image = resize_with_ratio(frame);

        imshow("resized image",image);    //显示摄像头的数据
        cv::cvtColor(image, input, cv::COLOR_BGR2RGB);

        // 下方的代码即将图像转化为Tensor，随后导入模型进行预测
        torch::Tensor tensor_image = torch::from_blob(input.data, {1,input.rows, input.cols,3}, torch::kByte);
        tensor_image = tensor_image.permute({0,3,1,2});
        tensor_image = tensor_image.toType(torch::kFloat);
        tensor_image = tensor_image.div(255);
        tensor_image = tensor_image.to(torch::kCUDA);
        torch::Tensor result = module->forward({tensor_image}).toTensor();

        auto max_result = result.max(1, true);
        auto max_index = std::get<1>(max_result).item<float>();
        if(max_index == 0)
            cv::putText(frame, "paper", {40, 50}, cv::FONT_HERSHEY_PLAIN, 2.0, cv::Scalar(0, 255, 0), 2);
        else if(max_index == 1)
            cv::putText(frame, "scissors", {40, 50}, cv::FONT_HERSHEY_PLAIN, 2.0, cv::Scalar(0, 255, 0), 2);
        else
            cv::putText(frame, "stone", {40, 50}, cv::FONT_HERSHEY_PLAIN, 2.0, cv::Scalar(0, 255, 0), 2);

        imshow("Gesture Detect",frame);    //显示摄像头的数据
        cv::waitKey(30);
    }

error: undefined reference to `cv::imread(std::string const&, int)'