Question

各位大侠，，最近在做图像处理的课设，。题目：用opencv函数从静态图片中检测出是否有人，

就是要检测出图片是否有人，从背面侧面都要检测出来，
最后提供思路，程序或者给相关链接 谢谢啦啦啦

Answer 1

下面这段代码可以实现对图像或者视频的人脸检测，你可以参考一下：
#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>

#ifdef _EiC
#define WIN32
#endif

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

void detect_and_draw( IplImage* image );

const char* cascade_name =
"haarcascade_frontalface_alt.xml";
/* "haarcascade_profileface.xml";*/

int main( int argc, char** argv )
{
CvCapture* capture = 0;
IplImage *frame, *frame_copy = 0;
int optlen = strlen("--cascade=");
const char* input_name;

if( argc > 1 && strncmp( argv[1], "--cascade=", optlen ) == 0 )
{
cascade_name = argv[1] + optlen;
input_name = argc > 2 ? argv[2] : 0;
}
else
{
cascade_name = "../../data/haarcascades/haarcascade_frontalface_alt2.xml";
//opencv装好后haarcascade_frontalface_alt2.xml的路径,
//也可以把这个文件拷到你的工程文件夹下然后不用写路径名cascade_name= "haarcascade_frontalface_alt2.xml";
//或者cascade_name ="C:\\Program Files\\OpenCV\\data\\haarcascades\\haarcascade_frontalface_alt2.xml"
input_name = argc > 1 ? argv[1] : 0;
}

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

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);

if( !input_name || (isdigit(input_name[0]) && input_name[1] == '\0') )
capture = cvCaptureFromCAM( !input_name ? 0 : input_name[0] - '0' );
else
capture = cvCaptureFromAVI( input_name );

cvNamedWindow( "result", 1 );

if( capture )
{
for(;;)
{
if( !cvGrabFrame( capture ))
break;
frame = cvRetrieveFrame( capture );
if( !frame )
break;
if( !frame_copy )
frame_copy = cvCreateImage( cvSize(frame->width,frame->height),
IPL_DEPTH_8U, frame->nChannels );
if( frame->origin == IPL_ORIGIN_TL )
cvCopy( frame, frame_copy, 0 );
else
cvFlip( frame, frame_copy, 0 );

detect_and_draw( frame_copy );

if( cvWaitKey( 10 ) >= 0 )
break;
}

cvReleaseImage( &frame_copy );
cvReleaseCapture( &capture );
}
else
{
const char* filename = input_name ? input_name : (char*)"lena.jpg";
IplImage* image = cvLoadImage( filename, 1 );

if( image )
{
detect_and_draw( image );
cvWaitKey(0);
cvReleaseImage( &image );
}
else
{
/* assume it is a text file containing the
list of the image filenames to be processed - one per line */
FILE* f = fopen( filename, "rt" );
if( f )
{
char buf[1000+1];
while( fgets( buf, 1000, f ) )
{
int len = (int)strlen(buf);
while( len > 0 && isspace(buf[len-1]) )
len--;
buf[len] = '\0';
image = cvLoadImage( buf, 1 );
if( image )
{
detect_and_draw( image );
cvWaitKey(0);
cvReleaseImage( &image );
}
}
fclose(f);
}
}

}

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 );
int i;

cvCvtColor( img, gray, CV_BGR2GRAY );
cvResize( gray, small_img, CV_INTER_LINEAR );
cvEqualizeHist( small_img, small_img );
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.) );
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);
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 );
}

追问

有没有是在图片中识别人的，从各个方向识别的，检测出是人就行了。。。。有还可以加分。。。。