opencv移植（二）

原文：https://blog.csdn.net/guet_kite/article/details/78667175?utm_source=copy 
版权声明：本文为博主原创文章，转载请附上博文链接！

接下来就是下载opencv了： 
下载地址： 

下载好之后解压：unzip opencv-2.4.11.zip
cd opencv-2.4.11.zip
建两个文件夹来存放配置和安装路径：
sudo mkdir /usr/local/opencv/install_opencv -d
sudo mkdir /usr/local/opencv/config_opencv -d

然后用cmake配置：
sudo cmake-gui

在where is the source code:里写上opencv的源文件路径 
在where to build the binaries:里面写上作为cmake编译arm版本的工作目录 
然后点击configure 

 

这里generator保持为unix makefiles，然后选择第四个选项：specify options for cross-compiling 
最后点击next

 

这里targeting system选的是linux（之前我选的是arm-linux，有点坑，选这个没有v4l支持），
接着就是选择工具链了，我用的是友善的4.4.3的工具链，compliers写的是交叉编译工具 arm-linux-gcc、arm-linux-g++
target root写的是交叉编译工具 arm-linux-g++/gcc 的所在包含文件夹
最后点击 finish即可

然后中间红色的配置里：
取消with_gtk
取消with_tiff
选择with_qt
gtk配置比较麻烦，我ubuntu之前就配置好有qt了，所以我们取消掉，直接用qt最gui。如果没有配置有qt，那还是不选吧。
最后点击configure，会发现有错误：error in configuration process,project files may be invalid
cmake warning at cmake/opencvfindlibsgui.cmake:18 (find_package):
by not providing “findqt5core.cmake” in cmake_module_path this project has
asked cmake to find a package configuration file provided by “qt5core”, but
cmake did not find one.

could not find a package configuration file provided by “qt5core” with any
of the following names:
qt5coreconfig.cmake
qt5core-config.cmake
第一个是一个warning，不管，下一个是error，说的是”qt5core”没找到。
我的qt安装路径是：/work/qt/my_qt/
所以直接把/work/qt/my_qt/lib/cmake/qt5core 填到qt5core_dir选项即可，
同理，底下几个选项也要填上，qt5gui_dir、qt5test_dir等…….

最后点击configure无误后，点击generate按钮就会在/usr/local/opencv/install_opencv目录生成makefile

cd /usr/local/opencv/config_opencv
修改安装opencv的路径：
sudo vi cmakecache.txt
找到：cmake_install_prefix:path=/usr/local
修改为：cmake_install_prefix:path=/usr/local/opencv/install_opencv
这是我自己的安装路径。

接着sudo make编译
最后把/usr/local/opencv/install_opencv/lib下文件移植到开发板根文件lib下 

好了，我们测试下： 
从网上找到一个测试例子,然后修改下，test.cpp：

#include <cv.h>
#include <cxcore.h>
#include <highgui.h>
#include <iostream>

using namespace std;

int main(int argc, char **argv)
{
         cvcapture* capture = null;
         iplimage* frame = null;
         if(!(capture = cvcapturefromcam(0))) {
                 cout<<"can not open camera.\n"<<endl;
                 return -1;
         }
         cvnamedwindow("video", 1);
         while(frame = cvqueryframe( capture )){
                  cvshowimage("video",frame);
                  cout<<"have capture\n"<<endl;
         }

         cout<<"no have capture\n"<<endl;
         cvdestroywindow("video");
         cvreleasecapture(&capture);
         return 0;
}

编译：

arm-linux-g++ -i/usr/local/opencv/install_opencv/include/opencv/ -l/usr/local/opencv/install_opencv/lib/ -lcv -lcxcore -lhighgui -lpthread -lrt -o test test.cpp

出现： 
test.cpp:21: note: the mangling of ‘va_list’ has changed in gcc 4.4 
在gcc 4.4里，’va_list’已经被改变了，所以我们编译时，要加上 -wno-psabi选项：

arm-linux-g++ -wno-psabi -i/usr/local/opencv/install_opencv/include/opencv/ -l/usr/local/opencv/install_opencv/lib/ -lcv -lcxcore -lhighgui -lpthread -lrt -o test test.cpp

那么，这样可以了吗？
不行！出现：
/usr/local/arm/opt/friendlyarm/toolschain/4.4.3/bin/../lib/gcc/arm-none-linux-gnueabi/4.4.3/../../../../arm-none-linux-gnueabi/bin/ld: cannot find -lcv
collect2: ld returned 1 exit status
这里提示lcv找不到，为什么呢？
还是我之前说的，网上的文章都是几年前的了，好老了。
打开我们opencv的lib可以看下，根本没有这些个库了，

所以提示自然找不到，所以要改成我们现在opencv的库：

arm-linux-g++ -wno-psabi -i/usr/local/opencv/install_opencv/include/opencv/ -l/usr/local/opencv/install_opencv/lib/ -lopencv_core -lopencv_highgui -lpthread -lrt -o test test.cpp

出现两个warning：
/usr/local/arm/opt/friendlyarm/toolschain/4.4.3/bin/../lib/gcc/arm-none-linux-gnueabi/4.4.3/../../../../arm-none-linux-gnueabi/bin/ld: warning: ../../lib/libopencv_imgproc.so, needed by /usr/local/opencv/lib_opencv/lib//libopencv_highgui.so, not found (try using -rpath or -rpath-link)
/usr/local/arm/opt/friendlyarm/toolschain/4.4.3/bin/../lib/gcc/arm-none-linux-gnueabi/4.4.3/../../../../arm-none-linux-gnueabi/bin/ld: warning: ../../lib/libopencv_core.so, needed by /usr/local/opencv/lib_opencv/lib//libopencv_highgui.so, not found (try using -rpath or -rpath-link)

将需要到的那三个.so文件:libopencv_core.so libopencv_highgui.so libopencv_imgproc.so将这些库复制到编译器的lib中：

sudo cp -d *libopencv_core* *libopencv_highgui* *libopencv_imgproc*  /usr/local/arm/opt/friendlyarm/toolschain/4.4.3/arm-none-linux-gnueabi/lib

 

然后把编译出来的test文件放到开发板上执行。

测试二：

 1 #include<opencv2/core/core.hpp>  
 2 #include<opencv2/highgui/highgui.hpp>  
 3 #include<iostream>
 4 
 5 using namespace cv;  
 6 using namespace std;
 7 
 8 int main( )  
 9 {   
10     //载入图片  
11     mat image= imread("girl.jpg");  
12     mat logo= imread("fly.jpg");   
13     //定义一个mat类型，用于存放，图像的roi  
14     mat imageroi;
15 
16     imageroi= image(rect(10,10,logo.cols,logo.rows));//定义一个左上角点坐标为(_x, _y)的cols*rows矩形窗口
17 
18     //将logo加到原图
19     //参数：图、权重、图、权重、添加的常数项、输出图
20     addweighted(imageroi,0.5,logo,0.3,0.,imageroi);     
21 
22     cout << "start add picture......\n" << endl;    
23     //输出一张jpg图片到工程目录下  
24     imwrite("fly_girl.jpg",image);  
25 
26     waitkey();  
27 
28     return 0;  
29 }  

makefile：

 1 cc  = arm-linux-g++
 2 lflags  = -wno-psabi
 3 libs    = -l/usr/local/opencv/install_opencv/lib/ -l/work/qt/my_qt/lib
 4 cppflags    = -lqt5widgets -lqt5gui -lqt5core -lpthread -lopencv_core -lopencv_highgui -lpthread -lrt
 5 linc     += -i/usr/local/opencv/install_opencv/include/opencv/
 6 objs := open
 7 out := open
 8 
 9 $(out):$(objs).cpp
10     ${cc} ${lflags} ${libs} ${linc} ${cppflags} -o $@ $^
11 
12 clean:
13     rm $(out)

 

 这是girl.jpg图： 

这是fly.jpg图：

这是使用opencv合成的效果图：