OpenCV_人脸检测

OpenCV_人脸检测

利用OpenCV自带的人脸识别库haarcascade_frontalface_alt.xml进行人脸识别测试

demo如下：

#include "cv.h"
#include "highgui.h"


#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <math.h>
#include <float.h>
#include <limits.h>
#include <time.h>
#include <ctype.h>
using namespace std;


static CvMemStorage* storage = 0;
static CvHaarClassifierCascade* cascade = 0;


void detect_and_draw( IplImage* image );


const char* cascade_name ="F:/ProgramFiles/opencv246/opencv/sources/data/haarcascades/haarcascade_frontalface_alt.xml"; //opencv自带人脸识别训练结果
/* "haarcascade_profileface.xml";*/


int main()
{
   CvCapture* capture = 0;


   cascade = (CvHaarClassifierCascade*)cvLoad( cascade_name, 0, 0, 0 );//加载opencv自带人脸识别训练结果


  if( !cascade )
  {
     fprintf( stderr, "ERROR: Could not load classifier cascade/n" );
     //fprintf( stderr,
     //"Usage: facedetect --cascade=/"<cascade_path>"/[filename|camera_index]/n" );
     return -1;
   }
   storage = cvCreateMemStorage(0);

   cvNamedWindow( "result", 1 );

   const char* filename = "people.jpg";
   IplImage* image = cvLoadImage(filename ); //加载图像
   if( image )
 {
 detect_and_draw( image );
 cvWaitKey(0);
 cvReleaseImage( &image );
 }


 cvDestroyWindow("result");
 cvWaitKey(0);
 return 0;
}


void detect_and_draw( IplImage* img ) //检测人脸并画出区域
{
 static CvScalar colors[] =   //随机生成颜色序列
 {
 {{0,0,255}},
 {{0,128,255}},
 {{0,255,255}},
 {{0,255,0}},
 {{255,128,0}},
 {{255,255,0}},
 {{255,0,0}},
 {{255,0,255}}
 };


 double scale = 1.3;
 IplImage* gray = cvCreateImage( cvSize(img->width,img->height), 8, 1 ); 
 IplImage* small_img = cvCreateImage( cvSize( cvRound (img->width/scale),
 cvRound (img->height/scale)),8, 1 );
 int i;


 cvCvtColor( img, gray, CV_BGR2GRAY );//彩色图转化为灰度图
 cvResize( gray, small_img, CV_INTER_LINEAR ); //利用线性插值算法归一化图像
 cvEqualizeHist( small_img, small_img ); //直方图均衡化
 cvClearMemStorage( storage );


 if( cascade )
 {
 double t = (double)cvGetTickCount(); 
 CvSeq* faces = cvHaarDetectObjects( small_img, cascade, storage,
 1.1, 2, 0/*CV_HAAR_DO_CANNY_PRUNING*/,
 cvSize(30, 30) );
 t = (double)cvGetTickCount() - t; 
 printf( "detection time = %gms/n", t/((double)cvGetTickFrequency()*1000.) ); //统计人脸定位所用时间
 for( i = 0; i < (faces ? faces->total : 0); i++ )
 {
 CvRect* r = (CvRect*)cvGetSeqElem( faces, i );
 CvPoint center;
 int radius;
 center.x = cvRound((r->x + r->width*0.5)*scale); //圆心
 center.y = cvRound((r->y + r->height*0.5)*scale);
 radius = cvRound((r->width + r->height)*0.25*scale); //半径
 cvCircle( img, center, radius, colors[i%8], 3, 8, 0 ); //用圆形圈出人脸区域
 }
 }


   cvShowImage( "result", img );
   cvReleaseImage( &gray );
  cvReleaseImage( &small_img );
} 

效果图：