Question

我只是按照说明在我的ubuntu计算机上安装opencv 3（我已经安装并在不同的Linux设备上使用opencv 3运行程序）但是，当我尝试运行其中一个我的旧计算机上的测试程序出现以下错误：

CMakeFiles/VideoTest.dir/VideoTest.cpp.o: In function `main':
VideoTest.cpp:(.text+0x6f): undefined reference to `cv::VideoWriter::fourcc(char,char,char, char)'
VideoTest.cpp:(.text+0xc3): undefined reference to `cv::VideoWriter::open(cv::String const&, int, double, cv::Size_<int>, bool)'
VideoTest.cpp:(.text+0x103): undefined reference to `cv::namedWindow(cv::String const&, int)'
VideoTest.cpp:(.text+0x146): undefined reference to `cv::VideoCapture::read(cv::_OutputArray const&)'
VideoTest.cpp:(.text+0x1b1): undefined reference to `cv::imshow(cv::String const&, cv::_InputArray const&)'
CMakeFiles/VideoTest.dir/VideoTest.cpp.o: In function `cv::String::String(char const*)':
VideoTest.cpp:(.text._ZN2cv6StringC2EPKc[_ZN2cv6StringC5EPKc]+0x3b): undefined reference to `cv::String::allocate(unsigned int)'
CMakeFiles/VideoTest.dir/VideoTest.cpp.o: In function `cv::String::~String()':
VideoTest.cpp:(.text._ZN2cv6StringD2Ev[_ZN2cv6StringD5Ev]+0xd): undefined reference to `cv::String::deallocate()'
collect2: ld returned 1 exit status
make[2]: *** [VideoTest] Error 1
make[1]: *** [CMakeFiles/VideoTest.dir/all] Error 2
make: *** [all] Error 2

知道发生了什么事吗？我对opencv比较陌生。这是我的测试代码供参考：

#include "opencv2/highgui/highgui.hpp"
#include "opencv2/opencv.hpp"
#include <iostream>

using namespace cv;
using namespace std;

int main(int argc, char* argv[]){
    VideoCapture vCap(0);
    VideoWriter vWrite;
    vWrite.open("test.avi", vWrite.fourcc('M','J','P','G'), 20, Size(640, 480), true);
    while (1) {
        namedWindow("VideoFeed", WINDOW_AUTOSIZE);
        Mat frame;
        vCap.read(frame);
        vWrite.write(frame);
        imshow("VideoFeed", frame);
        char c = waitKey(50);
        if (c == 27) {
            break;
        }
    }
    return 0;
}

提前致谢。

编辑：我的CMakeLists.txt：

cmake_minimum_required(VERSION 2.8)
project(VideoTest)
find_package(OpenCV REQUIRED)
add_executable(VideoTest VideoTest.cpp)
target_link_libraries(VideoTest ${OpenCV_LIBS})

Answer 1

VideoCapture和VideoWriter已移至3.0中的videoio模块，因此您必须另外

#include "opencv2/videoio.hpp"

另外，您似乎链接到任何所需的opencv库，它们是：

opencv_core, opencv_videoio, opencv_highgui

Answer 2

好吧，我终于弄清楚发生了什么。当我将目录移动到我的新系统时，CMakeFiles文件夹内部的东西变得棘手了。删除项目.cpp文件和CMakeLists.txt文件以外的所有文件/目录，然后运行“cmake”。再次“制造”似乎解决了这个问题。

Answer 3

cmake文件下面适用于我。

cmake_minimum_required(VERSION 3.5)
project(ImageProcessing)

set(CMAKE_CXX_STANDARD 14)
find_package(OpenCV REQUIRED)
include_directories( ${OpenCV_INCLUDE_DIRS} )
set(SOURCE_FILES main.cpp)
add_executable(ImageProcessing ${SOURCE_FILES})
target_link_libraries( ImageProcessing ${OpenCV_LIBS} )
# Print some message showing some of them
message(STATUS "OpenCV library status:")
message(STATUS "    version: ${OpenCV_VERSION}")
message(STATUS "    libraries: ${OpenCV_LIBS}")
message(STATUS "    include path: ${OpenCV_INCLUDE_DIRS}")

OpenCV 3.0未定义引用错误？

3 个答案: