matlab+opencv

部分转载已说明来源。

原文地址

另一篇

本人环境：matlab 2013 + VS2010 + opencv2.4.9

首先:matlab中输入 mex -setup 选择编译环境（我选的vs2010）

接下来测试一个matlab+c的混编程序.（下面的例子是实现a+b）

保存为.c或.cpp文件。我保存的是cvMexAdd.cpp

#include "mex.h"

double add(double x, double y)
{
return x * y;
}

//标准函数定义是:void mexFunction(int nlhs, mxArray *plhs[], int nrhs, const mxArray *prhs[])
//可以根据自己的喜欢修改变量名
/*
* nargout:输出变量数
* arrayout：输出数组指针
* nargin：输入变量数
* arrayin：输入数组指针
*/
void mexFunction(int nargout, mxArray *arrayout[], int nargin, const mxArray *arrayin[])
{
if(nargin != 2)//输入参数。(最好不要在编程的时候用中文，这里为了方便观察)
{
mexPrintf("输入参数要有2个.\n");
return;
}
double *a;
double b=1.0, c=2.0;
arrayout[0] = mxCreateDoubleMatrix(1, 1, mxREAL);
a = mxGetPr(arrayout[0]);
b = *(mxGetPr(arrayin[0]));
c = *(mxGetPr(arrayin[1]));
*a = add(b, c);
}
然后在matlab中输入 mex cvMexAdd.cpp

最后cvMexAdd(1,2)测试一下



接下来的怎么结合matlab+opencv就简单了。

假如matlab中已经写好了一个opencv的cpp程序如下：功能是实现一张图片转换成灰度图.我保存的名称是:cvRGB2Gray.cpp

// Interface: convert an image to gray and return to Matlab
// Author : zouxy
// Date : 2014-03-05
// HomePage : http://blog.csdn.net/zouxy09 // Email : zouxy09@qq.com

#include "opencv2\opencv.hpp"
#include "mex.h"

using namespace cv;

/*******************************************************
Usage: [imageMatrix] = RGB2Gray('imageFile.jpeg');
Input:
a image file
OutPut:
a matrix of image which can be read by Matlab

**********************************************************/

void exit_with_help()
{
mexPrintf(
"Usage: [imageMatrix] = DenseTrack('imageFile.jpg');\n"
);
}

static void fake_answer(mxArray *plhs[])
{
plhs[0] = mxCreateDoubleMatrix(0, 0, mxREAL);
}

void RGB2Gray(char *filename, mxArray *plhs[])
{
mexPrintf("Hello3!\n");
// read the image
Mat image = imread(filename);
if(image.empty()) {
mexPrintf("can't open input file %s\n", filename);
fake_answer(plhs);
return;
}

// convert it to gray format
Mat gray;
if (image.channels() == 3)
cvtColor(image, gray, CV_RGB2GRAY);
else
image.copyTo(gray);
imshow("gray",gray);
// convert the result to Matlab-supported format for returning
int rows = gray.rows;
int cols = gray.cols;
plhs[0] = mxCreateDoubleMatrix(rows, cols, mxREAL);

double *imgMat;
imgMat = mxGetPr(plhs[0]);
for (int i = 0; i < rows; i++)
{
for (int j = 0; j < cols; j++)
{
*(imgMat + i + j * rows) = (double)gray.at<uchar>(i, j);
}
}
}

void mexFunction(int nlhs, mxArray *plhs[], int nrhs, const mxArray *prhs[])
{
mexPrintf("Hello!\n");
if(nrhs == 1)
{
char filename[256];
mxGetString(prhs[0], filename, mxGetN(prhs[0]) + 1);
if(filename == NULL)
{
mexPrintf("Error: filename is NULL\n");
exit_with_help();
return;
}
mexPrintf("Hello2!\n");
RGB2Gray(filename, plhs);
}
else
{
exit_with_help();
fake_answer(plhs);
return;
}
}

我们编译他需要对matlab进行配置，并且编译的时候需要假如opencv的各种lib库文件，如果每一个文件都这么编译就非常麻烦。原文作者提供了一个类似makefile的代码，统一进行格式化处理，非常方便。代码是matlab的m文件，直接在matlab运行就可以了。
% 作者： Jessica 日期: 2014-9-10 主页: http://www.cnblogs.com/lukylu/ % Matlab and C++ mixed programming(dependent on opencv library)
% First step(before exeuting this program): use "mex -setup" to choose your c/c++ compiler
clear all;

% 判断系统位
is_64bit = strcmp(computer,'MACI64') || strcmp(computer,'GLNXA64') || strcmp(computer,'PCWIN64');

%-------------我的是64位系统，注意下面的配置需要手动修改几个地方---------------------
% Notice: if your system is 64bit, your OpenCV must be 64bit!
out_dir='./';

%你的opencv路径，我的是"d:/opencv" include的路径写在-I后面 lib路径写在-L后面
%如果你遇到问题，不放试一试x64或x86 或者用release调试，或者用debug调试(lib后面有d)

%一定要根据自己的opencv路径和版本修改对应的位置
CPPFLAGS = ' -O -DNDEBUG -I.\ -ID:\opencv\build\include -ID:\opencv\build\include\opencv -ID:\opencv\build\include\opencv2';
LDFLAGS = ' -LD:\opencv\build\x64\vc10\lib';    % your OpenCV "lib" path  mypath is "D:\opencv\.."
% LDFLAGS = '-LD:\opencv\build\x86\vc10\lib';
%LIBS = ' -lopencv_calib3d249d -lopencv_contrib249d -lopencv_core249d -lopencv_features2d249d -lopencv_flann249d -lopencv_gpu249d -lopencv_highgui249d -lopencv_imgproc249d -lopencv_legacy249d -lopencv_ml249d -lopencv_nonfree249d -lopencv_objdetect249d -lopencv_photo249d -lopencv_stitching249d -lopencv_ts249d -lopencv_video249d -lopencv_videostab249d';
LIBS = ' -lopencv_calib3d249 -lopencv_contrib249 -lopencv_core249 -lopencv_features2d249 -lopencv_flann249 -lopencv_gpu249 -lopencv_highgui249 -lopencv_imgproc249 -lopencv_legacy249 -lopencv_ml249 -lopencv_nonfree249 -lopencv_objdetect249 -lopencv_photo249 -lopencv_stitching249 -lopencv_ts249 -lopencv_video249 -lopencv_videostab249';
if is_64bit
CPPFLAGS = [CPPFLAGS ' -largeArrayDims'];
end

%你要编译的opencv程序
compile_files = {
%the list of your code files which need to be compiled
'cvRGB2Gray.cpp'
};
%----------------------------------------------------------------------------------------------

%----------------------------------------------------------------------------------------------
%% compiling
for k = 1 : length(compile_files)
str = compile_files{k};
fprintf('compilation of: %s\n', str);
str = [str ' -outdir ' out_dir CPPFLAGS LDFLAGS LIBS];
args = regexp(str, '\s+', 'split');
mex(args{:});
end
fprintf('Congratulations, compilation successful!!!\n');
%----------------------------------------------------------------------------------------------

我的运行结果：