matlab下mex 调用opencv库

1. 首先写好待编译的.cpp文件，使用混合编程，以人脸检测为例

#include "mex.h" // Required for the use of MEX files

// Required for OpenCV

#include "cv.h"

static CvMemStorage* storage = 0;

static CvHaarClassifierCascade* cascade = 0;

/** This is a the only prototype function that you need to get a mex file to work. */

void mexFunction(int output_size, mxArray *output[], int input_size, const mxArray *input[])

{

char *input_buf;

int buflen;

mxArray *xData;

double *xValues;

int i,j;

int NoOfCols, NoOfRows;

/* check for proper number of arguments */

if(input_size!=2)

mexErrMsgTxt("Usage: FaceDetect (<HaarCascade File>, <GrayImage>)");

/* input must be a string */

if ( mxIsChar(input[0]) != 1)

mexErrMsgTxt("Input 1 must be a string.");

/* get the length of the input string */

buflen = (mxGetM(input[0]) * mxGetN(input[0])) + 1;

/* copy the string data from input[0] into a C string input_ buf. */

input_buf = mxArrayToString(input[0]);

if(input_buf == NULL)

mexErrMsgTxt("Could not read HarrCascade Filename to string.");

// Read the Haar Cascade from the XML file

cascade = (CvHaarClassifierCascade*) cvLoad( input_buf, 0, 0, 0);

if( !cascade )

{

mexErrMsgTxt("ERROR: Could not load classifier cascade" );

}

/* Check if the input image is in double format*/

if (!(mxIsDouble(input[1]))) {

mexErrMsgTxt("Input image must be gray scale and of type double");

}

//Copy input pointer

// This carries the input grayscale image that was sent from Matlab

xData = (mxArray *)input[1];

//Get the matrix from the input data

// The matrix is rasterized in a column wise read

xValues = mxGetPr(xData);

NoOfCols = mxGetN(xData); // Gives the number of Columns in the image

NoOfRows = mxGetM(xData); // Gives the number of Rows in the image

/* Get the number of dimensions in the input Image */

int number_of_dims = mxGetNumberOfDimensions(input[1]);

if (number_of_dims > 2)

mexErrMsgTxt("Input image should be gray scale and of type double");

// Create an IplImage from the data so face detection can be run on it

IplImage* gray = cvCreateImage( cvSize(NoOfCols, NoOfRows), IPL_DEPTH_8U, 1 );

// Load the column wise vector into the IplImage

// IplImage data is read in a rowwise manner

// Appropriate conversion is carried out here

for(i=0;i<NoOfCols;i++)

for(j=0;j<NoOfRows;j++)

{

int value = xValues[(i*NoOfRows)+j];

gray->imageData[j*NoOfCols+i] = value;

}

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

* There is a bug in OpenCV that if one calls the cvLoad function before calling

* any other function from the cxCore lib, an error is thrown by the

* cvRead function that is part of cvLoad. In order to overcome this

* any function from the cxcore lib needs to be called. Here we create

* a dummy image 11x11 pixels in size and erode the image using a small

* kernel.

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

IplImage* dummy = cvCreateImage( cvSize(11, 11), IPL_DEPTH_8U, 1 ); // Make a dummy image

IplConvKernel* se = cvCreateStructuringElementEx(3,3,1,1,CV_SHAPE_ELLIPSE); // Create a filter

cvErode(dummy,dummy,se); // Erode

cvReleaseImage( &dummy );

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

* Detect faces *

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

// Histogram Equalize the image

cvEqualizeHist( gray, gray);

// This is required in the face detection process

storage = cvCreateMemStorage(0);

cvClearMemStorage( storage );

// Do Face Detection

CvSeq* faces = cvHaarDetectObjects( gray, cascade, storage,

1.1, 2, 0/*CV_HAAR_DO_CANNY_PRUNING*/,

cvSize(30, 30) );

// Allocate output variable

// Number of rows = number of detected faces

// Number of columns = 4

// 1: Location X of the face

// 2: Location Y of the face

// 3: Width of the face

// 4: Height of the face

double *Data;

if (faces->total)

{

output[0] = mxCreateDoubleMatrix(faces->total, 4, mxREAL);

Data = mxGetPr(output[0]); // Get the pointer to output variable

// Iterate trou each of the detected faces

for( i = 0; i < faces->total; i++ )

{

CvRect* r = (CvRect*)cvGetSeqElem( faces, i );

/* The Data pointer again has to be filled in a column wise manner

* The first column will contain the x location of all faces

* while column two will contain y location of all faces */

Data [i] = r->x;

Data [i+faces->total] = r->y;

Data [i+faces->total*2] = r->width;

Data [i+faces->total*3] = r->height;

// Debug

// printf ("%d %d %d %d\n", r->x, r->y, r->width, r->height);

}

}

else

{

output[0] = mxCreateDoubleMatrix(1, 1, mxREAL);

Data = mxGetPr(output[0]); // Get the pointer to output variable

Data[0] = -1;

}

// Release all the memory

cvReleaseImage( &gray );

cvReleaseMemStorage(&storage);

cvReleaseHaarClassifierCascade(&cascade);

return;

}

2. 写好待mex 的.m文件（转自http://www.cnblogs.com/lukylu/p/3966871.html）

注意这里要把opencv的bin目录（C:\opencv\build\x64\vc10\bin）添加到环境变量里，重启电脑。

mex -setup 的时候去与之相应的c++ vs2010 编译器。

clear all;

% Get the architecture of this computer

is_64bit = strcmp(computer,'MACI64') || strcmp(computer,'GLNXA64') || strcmp(computer,'PCWIN64');

%----------------------------------------------------------------------------------------------

%% The configuration of compiler

% You need to modify this configuration according to your own path of OpenCV

% Notice: if your system is 64bit, your OpenCV must be 64bit!

out_dir='./';

CPPFLAGS = ' -O -DNDEBUG -I.\ -IC:\opencv\build\include -IC:\opencv\build\include\opencv -IC:\opencv\build\include\opencv2'; % your OpenCV "include" path

LDFLAGS = ' -LC:\opencv\build\x64\vc10\lib'; % your OpenCV "lib" path

%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

% add your files here!!

compile_files = {

%the list of your code files which need to be compiled

% 'ImageCalibration.cpp'

'FaceDetect.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');