openCV -Step1 Display image with C/C++

1.編寫一個 C/C++ 語言程式檔 displayimage.cpp，程式碼如下：

#include <stdio.h>
#include <opencv2/opencv.hpp>

using namespace cv;

int main(int argc, char **argv )
{
    if ( !argc[2] )
    {
        printf("usage: DisplayImage <Image_Path>\n");
        return -1;
    }

    Mat image;
    image = imread( argv[1], 1 );

    if ( !image.data )
    {
        printf("No image data \n");
        return -1;
    }
    namedWindow("DisplayImage", WINDOW_AUTOSIZE );
    imshow("DisplayImage", image);

    waitKey(0);

    return 0;
}

2.編寫一個 CMakeLists.txt 檔，程式碼如下：

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

3.將1、2點的檔案和任意圖檔(XXX.png)放在同一個目錄 displayimage 底下，執行 cmake .，之後執行 make :

$ cmake .
$ make

執行最後會顯示下列訊息：
...
-- Build files have been written to: /home/<username>/.../DisplayImage
4.會出現一個叫 DisplayImage 的可執行檔，並執行下列指令：

$ ./DisplayImage XXX.png

即可用opencV 顯示圖片

參考資料：
www.google.com
http://www.bogotobogo.com/OpenCV/opencv_3_tutorial_ubuntu14_install_cmake.php
http://blog.csdn.net/poem_qianmo/article/details/20537737