[学习OpenCV攻略][017][ARM9下移植OpenCV]

安装环境

宿主机：

Red Hat Enterprise Linux Server 6.3

开发板：

mini2440

相关软件：

cmake-3.5.1.tar.gz、OpenCV-2.3.1a.tar.bz2

下载地址：

CMake:

https://cmake.org/files/v3.5/cmake-3.5.1.tar.gz

OpenCV:

http://downloads.sourceforge.net/project/opencvlibrary/opencv-unix/2.3.1/OpenCV-2.3.1a.tar.bz2

安装过程

CMake安装

说明：

CMake是一个跨平台的安装(编译)工具,可以用简单的语句来描述所有平台的安装(编译过程)。用它来产生OpenCV编译时用到的Makefile文件。

步骤：

1.解压

tar xvf cmake-3.5.1.tar.gz

cd cmake-3.5.1

2.配置

./configure --prefix=/usr //生成Makefile,安装位置/usr

3.编译

make //通过Makefile编译源代码

4.安装

make install //文件安装在/usr/路径下

5.测试

cmake //执行cmake命令显示cmake版本号和帮助信息表示安装成功

OpenCV安装

说明：

OpenCV是一个基于BSD许可（开源）发行的跨平台计算机视觉库。编译和运行调用OpenCV库函数的程序时需要用到OpenCV库和头文件。

1.解压

tar xvf OpenCV-2.3.1a.tar.bz2

cd OpenCV-2.3.1

2.配置

2.1.编写配置文件

vim toolchain.cmake

# this one is important
SET(CMAKE_SYSTEM_NAME Linux)

# specify the cross compiler
SET(CMAKE_C_COMPILER   /usr/local/arm/4.3.2/bin/arm-linux-gcc)
SET(CMAKE_CXX_COMPILER /usr/local/arm/4.3.2/bin/arm-linux-g++)

# where is the target environment 
SET(CMAKE_FIND_ROOT_PATH /usr/local/arm/4.3.2)

# search for programs in the build host directories
SET(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
# for libraries and headers in the target directories
SET(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
SET(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)

2.2.生成编译文件

mkdir _install //创建安装目录

cmake -DCMAKE_TOOLCHAIN_FILE=toolchain.cmake -DCMAKE_INSTALL_PREFIX=${PWD}/_install/ //生成Makefile

2.3.修改编译文件

ccmake .

WITH_FFMPEG                      OFF   //关闭视频解码，如果需要先编译相关库
WITH_GSTREAMER                   OFF   //关闭视频解码，如果需要先编译相关库
WITH_GTK                         OFF   //关闭图形界面，如果需要先编译相关库
WITH_TIFF                        OFF   //关闭图片格式，如果需要先编译相关库

按下c生效配置，按下e退出配置，按下q退出配置。

3.编译

make //通过Makefile编译源代码

如果遇到错误：

/space/work/thesis/000/OpenCV-2.3.1/modules/flann/include/opencv2/flann/dist.h:63:error: 'fabsl' was not declared in this scope。

修改fabsl为fabs，然后继续make。

如果遇到错误：

Linking CXX executable ../../bin/opencv_test_calib3d

../../lib/libopencv_core.so: undefined reference to `pthread_key_create'

../../lib/libopencv_core.so: undefined reference to `pthread_getspecific'

../../lib/libopencv_ts.so: undefined reference to `pthread_key_delete'

../../lib/libopencv_core.so: undefined reference to `pthread_once'

../../lib/libopencv_core.so: undefined reference to `clock_gettime'

../../lib/libopencv_core.so: undefined reference to `pthread_setspecific'

collect2: ld returned 1 exit status

修改/opt/opencv2.3.1目录下的CMakeCache.txt，CMAKE_EXE_LINKER_FLAGS原来为空，加上-lpthread –lrt，然后继续make。

4.安装

make install //文件安装在${PWD}/_install/路径下

5.测试

5.1.编写Makefile

vim Makefile

prefix = .../OpenCV-2.3.1/_install
libdir = $(prefix)/lib
includedir_old = $(prefix)/include/opencv
includedir_new = $(prefix)/include

Libs  = -L$(libdir) -lopencv_core -lopencv_imgproc -lopencv_highgui -lopencv_ml -lopencv_video -lopencv_features2d -lopencv_calib3d -lopencv_objdetect -lopencv_contrib -lopencv_legacy -lopencv_flann
Cflag = -I$(includedir_old) -I$(includedir_new)

% : %.c
    arm-linux-g++ $(Libs) $(Cflag) $^ -o $@

% : %.cpp
    arm-linux-g++ $(Libs) $(Cflag) $^ -o $@

5.2.编写测试程序

vim test.cpp

#include <stdio.h>
#include <cv.h>
#include <highgui.h>

using namespace cv;

int main(int argc, char **argv){
    //参数检测
    if(argc != 2){
        printf("Usage:\n\%s <image.jpg>", argv[1]);
    }
    
    //打开图片
    Mat src;
    
    src = imread(argv[1], 0);   //灰度转换
    
    //保存图片
    imwrite("dst.jpg", src);
    
    return 0;
}