opencv2.4.9在ubuntu(树莓派)上安装

参考原文：https://my.oschina.net/u/1757926/blog/293976

1. 先从sourceforge上下载OpenCV的源码

1. http://jaist.dl.sourceforge.net/project/opencvlibrary/opencv-unix/2.4.9/opencv-2.4.9.zip

2. 解压到任意目录

1. unzip opencv-2.4.9.zip

3. 进入源码目录，创建release目录

1. cd opencv-2.4.9

2. mkdir release  

4. 可以看到在OpenCV目录下，有个CMakeLists.txt文件，需要事先安装一些软件

1. sudo apt-get install build-essential cmake libgtk2.0-dev pkg-config python-dev python-numpy libavcodec-dev libavformat-dev libswscale-dev  

5.  新建release目录，并进入release目录，安装OpenCV是所有的文件都会被放到这个release目录下

1. cd release  

6. cmake编译OpenCV源码，安装所有的lib文件都会被安装到/usr/local目录下

1. cmake -D CMAKE_BUILD_TYPE=RELEASE -D WITH_FFMPEG=OFF -D CMAKE_INSTALL_PREFIX=/usr/local ..  

7. 安装

1. sudo make install  

8. 测试，在某个目录下建立一个test.cpp文件

#include <cv.h>  
#include <highgui.h>  
  
using namespace cv;  
  
int main(int argc, char* argv[])  
{  
    Mat image;  
    image = imread(argv[1], 1);  
  
    if (argc != 2 || !image.data)   
    {  
        printf("No image data ");  
        return -1;  
    }  
  
    namedWindow("Display Image", CV_WINDOW_AUTOSIZE);  
    imshow("Display Image", image);  
    waitKey(0);  
    return 0;  
}

9. 写一个cmake的makefile，也叫CMakeLists.txt

project(test)  
find_package(OpenCV REQUIRED)  
add_executable(test test)  
target_link_libraries(test ${OpenCV_LIBS})  
cmake_minimum_required(VERSION 2.8)

10. 编译+运行

1. cmake .  

2. make  

3. 得到可执行文件test10. 编译+运行

11.安装树莓派时会出现

error when trying to build opencv 2.4.9 

home/greg/Applications/opencv-2.4.10/modules/highgui/src/ffmpeg_codecs.hpp:104:7: error: ‘CODEC_ID_H264’ was not declared in this scope
     { CODEC_ID_H264, MKTAG('H', '2', '6', '4') },
       ^

解决方式：cmake ......... -D WITH_FFMPEG=OFF

12. 打开摄像头

int main()

{

VideoCapture cap(0);
if(!cap.isOpened())
{
printf("camera open faile! ");
return -1;
}
namedWindow("hhh", CV_WINDOW_AUTOSIZE);
while(1)
{
Mat frame;
cap>>frame;
imshow("hhh",frame);
waitKey(30);
}

return 0;

}