c++ - opencv2 可以使用 cmake 构建但不能在 CLion "build"功能中构建？

Question

我很困惑为什么我可以在命令行中使用 cmake 构建 C++ 程序，但不能在 CLion 中使用其“构建”功能构建程序。

这是我的 CMakeLists.txt 文件。我正在尝试使用 OpenCV 构建一个简单的图像分类程序，教程是 here .

cmake_minimum_required(VERSION 3.5.1)
project(opencvdnn )

set(CMAKE_CXX_STANDARD 14)

find_package( OpenCV REQUIRED )
include_directories( ${OpenCV_INCLUDE_DIRS} )

add_executable(caffe caffe.cpp)
target_link_libraries(caffe ${OpenCV_LIBS} )

案例 1:

我直接在命令行中使用以下命令和结果成功构建:

user:/DATA/opencvdnn/build$ cmake ../CMakeLists.txt

-- The C compiler identification is GNU 5.4.0
-- The CXX compiler identification is GNU 5.4.0
-- Check for working C compiler: /usr/bin/cc
-- Check for working C compiler: /usr/bin/cc -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Detecting C compile features
-- Detecting C compile features - done
-- Check for working CXX compiler: /usr/bin/c++
-- Check for working CXX compiler: /usr/bin/c++ -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Configuring done
-- Generating done
-- Build files have been written to: /media/yuqiong/DATA/opencvdnn

案例二

我在我的 CLion IDE 中使用 build 功能，但失败了，声称找不到某个库。

/opt/clion-2018.2.5/bin/cmake/linux/bin/cmake --build /media/yuqiong/DATA/opencvdnn --target caffe -- -j 6
Scanning dependencies of target caffe
[ 50%] Building CXX object CMakeFiles/caffe.dir/caffe.cpp.o
/media/yuqiong/DATA/opencvdnn/caffe.cpp:5:27: fatal error: opencv2/dnn.hpp: No such file or directory
compilation terminated.
CMakeFiles/caffe.dir/build.make:62: recipe for target 'CMakeFiles/caffe.dir/caffe.cpp.o' failed
make[3]: *** [CMakeFiles/caffe.dir/caffe.cpp.o] Error 1
CMakeFiles/Makefile2:67: recipe for target 'CMakeFiles/caffe.dir/all' failed
make[2]: *** [CMakeFiles/caffe.dir/all] Error 2
CMakeFiles/Makefile2:79: recipe for target 'CMakeFiles/caffe.dir/rule' failed
make[1]: *** [CMakeFiles/caffe.dir/rule] Error 2
Makefile:118: recipe for target 'caffe' failed
make: *** [caffe] Error 2

我的问题是为什么会这样？ CLion 是否使用与 cmake 工具相同的 CMake？谢谢!

如果有帮助，这是我的目录结构:

├── build
├── bvlc_googlenet.caffemodel
├── bvlc_googlenet.prototxt
├── caffe.cpp
├── cmake-build-debug
│   ├── CMakeCache.txt
│   ├── CMakeFiles
│   │   ├── 3.12.3
│   │   │   ├── CMakeCCompiler.cmake
│   │   │   ├── CMakeCXXCompiler.cmake
│   │   │   ├── CMakeDetermineCompilerABI_C.bin
│   │   │   ├── CMakeDetermineCompilerABI_CXX.bin
│   │   │   ├── CMakeSystem.cmake
│   │   │   ├── CompilerIdC
│   │   │   │   ├── a.out
│   │   │   │   ├── CMakeCCompilerId.c
│   │   │   │   └── tmp
│   │   │   ├── CompilerIdCUDA
│   │   │   │   ├── CMakeCUDACompilerId.cu
│   │   │   │   └── tmp
│   │   │   └── CompilerIdCXX
│   │   │       ├── a.out
│   │   │       ├── CMakeCXXCompilerId.cpp
│   │   │       └── tmp
│   │   ├── caffe.dir
│   │   │   ├── build.make
│   │   │   ├── cmake_clean.cmake
│   │   │   ├── CXX.includecache
│   │   │   ├── DependInfo.cmake
│   │   │   ├── depend.internal
│   │   │   ├── depend.make
│   │   │   ├── flags.make
│   │   │   ├── link.txt
│   │   │   └── progress.make
│   │   ├── clion-environment.txt
│   │   ├── clion-log.txt
│   │   ├── cmake.check_cache
│   │   ├── CMakeDirectoryInformation.cmake
│   │   ├── CMakeError.log
│   │   ├── CMakeOutput.log
│   │   ├── CMakeTmp
│   │   ├── feature_tests.bin
│   │   ├── feature_tests.c
│   │   ├── feature_tests.cxx
│   │   ├── Makefile2
│   │   ├── Makefile.cmake
│   │   ├── opencvdnn.dir
│   │   │   ├── build.make
│   │   │   ├── cmake_clean.cmake
│   │   │   ├── DependInfo.cmake
│   │   │   ├── depend.make
│   │   │   ├── flags.make
│   │   │   ├── link.txt
│   │   │   └── progress.make
│   │   ├── Progress
│   │   │   ├── 1
│   │   │   └── count.txt
│   │   ├── progress.marks
│   │   └── TargetDirectories.txt
│   ├── cmake_install.cmake
│   ├── Makefile
│   └── opencvdnn.cbp
├── CMakeCache.txt
├── CMakeFiles
│   ├── 3.12.3
│   │   ├── CMakeCCompiler.cmake
│   │   ├── CMakeCXXCompiler.cmake
│   │   ├── CMakeDetermineCompilerABI_C.bin
│   │   ├── CMakeDetermineCompilerABI_CXX.bin
│   │   ├── CMakeSystem.cmake
│   │   ├── CompilerIdC
│   │   │   ├── a.out
│   │   │   ├── CMakeCCompilerId.c
│   │   │   └── tmp
│   │   └── CompilerIdCXX
│   │       ├── a.out
│   │       ├── CMakeCXXCompilerId.cpp
│   │       └── tmp
│   ├── 3.5.1
│   │   ├── CMakeCCompiler.cmake
│   │   ├── CMakeCXXCompiler.cmake
│   │   ├── CMakeDetermineCompilerABI_C.bin
│   │   ├── CMakeDetermineCompilerABI_CXX.bin
│   │   ├── CMakeSystem.cmake
│   │   ├── CompilerIdC
│   │   │   ├── a.out
│   │   │   └── CMakeCCompilerId.c
│   │   └── CompilerIdCXX
│   │       ├── a.out
│   │       └── CMakeCXXCompilerId.cpp
│   ├── caffe.dir
│   │   ├── build.make
│   │   ├── cmake_clean.cmake
│   │   ├── DependInfo.cmake
│   │   ├── depend.make
│   │   ├── flags.make
│   │   ├── link.txt
│   │   └── progress.make
│   ├── clion-environment.txt
│   ├── cmake.check_cache
│   ├── CMakeDirectoryInformation.cmake
│   ├── CMakeOutput.log
│   ├── CMakeTmp
│   ├── feature_tests.bin
│   ├── feature_tests.c
│   ├── feature_tests.cxx
│   ├── Makefile2
│   ├── Makefile.cmake
│   ├── progress.marks
│   └── TargetDirectories.txt
├── cmake_install.cmake
├── CMakeLists.txt
├── Makefile
├── opencvdnn.cbp
├── space_shuttle.jpg
└── synset_words.txt

这是源代码，它基本上只是读取 caffe 模型并将其用于图像。

#include <opencv2/dnn.hpp>
#include <opencv2/imgproc.hpp>
#include <opencv2/highgui.hpp>
#include <opencv2/core/utils/trace.hpp>
using namespace cv;
using namespace cv::dnn;
#include <fstream>
#include <iostream>
#include <cstdlib>
using namespace std;
/* Find best class for the blob (i. e. class with maximal probability) */
static void getMaxClass(const Mat &probBlob, int *classId, double *classProb)
{
    Mat probMat = probBlob.reshape(1, 1); //reshape the blob to 2x1000 matrix
    Point classNumber;
    minMaxLoc(probMat, NULL, classProb, NULL, &classNumber);
    *classId = classNumber.x;
}
static std::vector<String> readClassNames(const char *filename = "synset_words.txt")
{
    std::vector<String> classNames;
    std::ifstream fp(filename);
    if (!fp.is_open())
    {
        std::cerr << "File with classes labels not found: " << filename << std::endl;
        exit(-1);
    }
    std::string name;
    while (!fp.eof())
    {
        std::getline(fp, name);
        if (name.length())
            classNames.push_back( name.substr(name.find(' ')+1) );
    }
    fp.close();
    return classNames;
}
int main(int argc, char **argv)
{
    CV_TRACE_FUNCTION();
    String modelTxt = "bvlc_googlenet.prototxt";
    String modelBin = "bvlc_googlenet.caffemodel";
    String imageFile = (argc > 1) ? argv[1] : "space_shuttle.jpg";
    Net net;
    try {
        net = dnn::readNetFromCaffe(modelTxt, modelBin);
    }
    catch (cv::Exception& e) {
        std::cerr << "Exception: " << e.what() << std::endl;
        if (net.empty())
        {
            std::cerr << "Can't load network by using the following files: " << std::endl;
            std::cerr << "prototxt:   " << modelTxt << std::endl;
            std::cerr << "caffemodel: " << modelBin << std::endl;
            std::cerr << "bvlc_googlenet.caffemodel can be downloaded here:" << std::endl;
            std::cerr << "http://dl.caffe.berkeleyvision.org/bvlc_googlenet.caffemodel" << std::endl;
            exit(-1);
        }
    }
    Mat img = imread(imageFile);
    if (img.empty())
    {
        std::cerr << "Can't read image from the file: " << imageFile << std::endl;
        exit(-1);
    }
    //GoogLeNet accepts only 224x224 BGR-images
    Mat inputBlob = blobFromImage(img, 1.0f, Size(224, 224),
                                  Scalar(104, 117, 123), false);   //Convert Mat to batch of images
    Mat prob;
    cv::TickMeter t;
    for (int i = 0; i < 10; i++)
    {
        CV_TRACE_REGION("forward");
        net.setInput(inputBlob, "data");        //set the network input
        t.start();
        prob = net.forward("prob");                          //compute output
        t.stop();
    }
    int classId;
    double classProb;
    getMaxClass(prob, &classId, &classProb);//find the best class
    std::vector<String> classNames = readClassNames();
    std::cout << "Best class: #" << classId << " '" << classNames.at(classId) << "'" << std::endl;
    std::cout << "Probability: " << classProb * 100 << "%" << std::endl;
    std::cout << "Time: " << (double)t.getTimeMilli() / t.getCounter() << " ms (average from " << t.getCounter() << " iterations)" << std::endl;
    return 0;
} //main

Answer 1

恐怕您使用命令行的第一种方法不起作用。 cmake 只会创建 make 文件。它是实际构建目标的 make 命令。您的 clion 输出表明 clion 能够成功生成 make 文件，但无法构建。如果您尝试通过命令行手动执行 make，我希望会出现相同的错误。

如果您可以通过命令行构建 camke 项目，它也应该 100% 地在 clion 中构建。

我还建议检查您的系统上是否安装了 opencv2。检查您是否有文件夹/usr/include/opencv 或者它是否是/usr/include/opencv2。由于您的 find_package(OpenCV REQUIRED) 成功，可以肯定您有本地安装。

另一种方法是查找文件 CMakeCache.txt。如果你在其中搜索 opencv，你会发现其中设置了一些 OpenCV 变量。这应该会给你一个线索。