单张图片人脸检测



使用xml（haarcascade_frontalface_alt.xml）实现人脸检测

#include "stdafx.h" 
#include "cv.h"  
#include "highgui.h" 
#include <stdio.h>   
static CvHaarClassifierCascade* cascade = 0; 
static CvMemStorage* storage = 0;   
void detect_and_draw( IplImage* image );  
const char* cascade_name ="haarcascade_frontalface_alt.xml"; 

int _tmain(int argc, _TCHAR* argv[])  
{       
	cascade = (CvHaarClassifierCascade*)cvLoad( cascade_name, 0, 0, 0 );   //加载人脸检测所用的分类器      
	if( !cascade )      
	{          
		fprintf( stderr, "ERROR: Could not load classifier cascade\n" );
		return -1;      
	}       
	storage = cvCreateMemStorage(0);                                       //动态存储结构，用来存储人脸在图像中的位置      
	cvNamedWindow( "result", 1 );       //const char* filename = "lena.jpg";                                     //待检测图像(包含绝对路径)   
	const char* filename = "景甜.jpg";       
	IplImage* image = cvLoadImage( filename, 1 );                          //加载图像      
	detect_and_draw( image );                                              //对加载的图像进行检测      
	cvWaitKey(0);       
	cvReleaseImage( &image );      
	cvDestroyWindow("result");      
	return 0; }   
void detect_and_draw( IplImage* img ) 
{      
	static CvScalar colors[] =      
	{          
		{{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 );        
	cvCvtColor( img, gray, CV_BGR2GRAY );      
	cvResize( gray, small_img, CV_INTER_LINEAR );  
	cvEqualizeHist( small_img, small_img );     
	cvClearMemStorage( storage );        
	if( cascade )     
	{          
		/*函数cvHaarDetectObjects检测图像中的目标，由OpenCV提供。*/         
		CvSeq* faces = cvHaarDetectObjects( small_img, cascade, storage, 1.1, 2, 0 ,                                             
			cvSize(30, 30) );         
		for( int 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);             
			center.y = cvRound((r->y + r->height*0.5)*scale);             
			radius = cvRound((r->width + r->height)*0.25*scale);             
			cvCircle( img, center, radius, colors[i%8], 3, 8, 0 );         
		}     
	}        
	cvShowImage( "result", img );     
	cvReleaseImage( &gray );      
	cvReleaseImage( &small_img ); 
}