Linux下使用Opencv打开笔记本摄像头

新建test文件夹，文件夹存在test.cpp和CMakeLists.txt

test.cpp
#include <iostream>
#include <string>
#include <sstream>

#include <opencv2/core.hpp>
#include <opencv2/highgui.hpp>
#include <opencv2/videoio.hpp> 

using namespace cv;
using namespace std;

const char* keys = 
{
    "{help h usage ? | | print this message}"
    "{@video | | Video file, if not defined try to use webcamera}"
};

int main(int argc, const char** argv)
{
    CommandLineParser parser(argc, argv, keys);
    parser.about("Reading a video and camera v1.0.0");

    if (parser.has("help"))
    {
        parser.printMessage();
        return 0;
    }
    String videoFile = parser.get<String>(0);

    if (!parser.check())
    {
        parser.printErrors();
        return 0;
    }

    VideoCapture cap; 
    if (videoFile != "")
    {
        cap.open(videoFile);// read a video file
    }else {
        cap.open(0);// read the default caera
    }
    if (!cap.isOpened())// check if we succeeded
    {
        return -1;
    }

    namedWindow("Video", 1);
    while (1)
    {
        Mat frame;
        cap >> frame; // get a new frame from camera
        imshow("Video", frame);
        if (waitKey(30) >= 0) break;
    }

    // Release the camera or video file
    cap.release();
    return 0;
}

CMakeLists.txt

project(test)

cmake_minimum_required(VERSION 2.8.7)

# option to enable OpenMP; only relevant for the KCF version with the
# VOT scale estimation
option(WITH_OPENMP "Enable OpenMP" OFF)

if(WITH_OPENMP)
    find_package(OpenMP REQUIRED)

    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${OpenMP_CXX_FLAGS}")
    set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} ${OpenMP_EXE_LINKER_FLAGS}")
endif(WITH_OPENMP)

# add c++11 support
if(CMAKE_COMPILER_IS_GNUCC)
    ADD_DEFINITIONS ( -std=c++11 )
endif(CMAKE_COMPILER_IS_GNUCC)

# add OpenCV
set(OPENCV_DIR_HINT "")

if(WIN32)
    get_filename_component(OPENCV_DIR_PLATFORM $ENV{OPENCV_DIR} DIRECTORY)
    get_filename_component(OPENCV_DIR_HINT ${OPENCV_DIR_PLATFORM} DIRECTORY)
endif(WIN32)

set(OpenCV_STATIC OFF)
find_package(OpenCV REQUIRED HINTS ${OPENCV_DIR_HINT})

编译过程：

> cd test
> g++ test.cpp -o test `pkg-config --cflags --libs opencv`
> ./test