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

openCV -Step0 Building openCV on Debian Linux

1.至 openCV 官方網站下載函式庫，裏面有很多種版本，我裝的是最新版 VERSION 3.4:

   從openCV的GitHub下載檔案，指令如下: 
    $ git clone https://github.com/opencv/opencv.git

2.將電腦更新並且下載需要的套件：

# apt-get update

# apt-get install libopencv-dev build-essential checkinstall cmake pkg-config yasm libtiff5-dev libjpeg-dev libjasper-dev libavcodec-dev libavformat-dev libswscale-dev libdc1394-22-dev libxine2-dev libgstreamer0.10-dev libgstreamer-plugins-base0.10-dev libv4l-dev python-dev python-numpy libtbb-dev libqt4-dev libgtk2.0-dev libfaac-dev libmp3lame-dev libopencore-amrnb-dev libopencore-amrwb-dev libtheora-dev libvorbis-dev libxvidcore-dev x264 v4l-utils ffmpeg

3.將 openCV 官網抓下來的 opencv-3.4.zip 解壓縮，進入 opencv-3.4裡面建立 release 資料夾，再 release 裡面執行一串cmake 程序：

$ cmake -D CMAKE_BUILD_TYPE=RELEASE -D CMAKE_INSTALL_PREFIX=/usr/local -D WITH_TBB=ON -D BUILD_NEW_PYTHON_SUPPORT=ON -D WITH_V4L=ON -D INSTALL_C_EXAMPLES=ON -D INSTALL_PYTHON_EXAMPLES=ON -D BUILD_EXAMPLES=ON -D WITH_QT=ON -D WITH_OPENGL=ON ..

執行最後會顯示下列訊息：

...

-- Build files have been written to: /home/<username>/.../opencv-3.1.0/release

4.接著執行 make 和 make install 即可完成 openCV的環境建置：

$ make

# make install

5.參考網址：

http://www.bogotobogo.com/cplusplus/opencv.php

http://docs.opencv.org/2.4/index.html