//背景法 --- 只能用于背景场景中不包含运动的部分//为需要的不同临时图像和统计属性图像创建指针
IplImage *IavgF,IdiffF,*IprevF,*IhiF,*IlowF;
IplImage*Iscratch,*Iscratch2;
IplImage*Igray1,*Igray2,*Igray3;
IplImage*Ilow1,*Ilow2,*Ilow3;
IplImage*Ihi1,*Ihi2,*Ihi3;
IplImage*Imaskt;float Icount; //couts number of images learned for averaging later//创建一个函数给需要的所有临时图像分配内存
void AllocateImages(IplImage*I)
{
CvSize sz=cvGetSize(I);
IavgF=cvCreateImage(sz,IPL_DEPTH_32F,3);
IdiffF=cvCreateImage(sz,IPL_DEPTH_32F,3);
IprevF=cvCreateImage(sz,IPL_DEPTH_32F,3);
IhiF=cvCreateImage(sz,IPL_DEPTH_32F,3);
IlowF=cvCreateImage(sz,IPL_DEPTH_32F,3);
Ilow1=cvCreateImage(sz,IPL_DEPTH_32F,1);
Ilow2=cvCreateImage(sz,IPL_DEPTH_32F,1);
Ilow3=cvCreateImage(sz,IPL_DEPTH_32F,1);
Ihi1=cvCreateImage(sz,IPL_DEPTH_32F,1);
Ihi2=cvCreateImage(sz,IPL_DEPTH_32F,1);
Ihi3=cvCreateImage(sz,IPL_DEPTH_32F,1);
cvZero(IavgF);
cvZero(IdiffF);
cvZero(IprevF);
cvZero(IhiF);
cvZero(IlowF);
Icount= 0.00001; //Protect against divide by zero
Iscratch=cvCreateImage(sz,IPL_DEPTH_32F,3);
Iscratch2=cvCreateImage(sz,IPL_DEPTH_32F,3);
Igray1=cvCreateImage(sz,IPL_DEPTH_32F,1);
Igray2=cvCreateImage(sz,IPL_DEPTH_32F,1);
Igray3=cvCreateImage(sz,IPL_DEPTH_32F,1);
Imaskt=cvCreateImage(sz,IPL_DEPTH_32F,1);
cvZero(Iscratch);
cvZero(Iscratch2);
}//学习积累背景图像和每一帧图像差值的绝对值
void accumulateBackground(IplImage*I)
{static int first=1;
cvCvtScale(I,Iscratch,1,0);if (!first)
{
cvAcc(Iscratch,IavgF);
cvAbsDiff(Iscratch,IprevF,Iscratch2);
cvAcc(Iscratch,IdiffF);
Icount+=1.0;
}
first=0;
cvCopy(Iscratch,IprevF);
}void setHighThreshold(floatscale)
{
cvConvertScale(IdiffF,Iscratch,scale);
cvAdd(Iscratch,IavgF,IhiF);
cvSplit(IhiF,Ihi1,Ihi2,Ihi3,0);
}void setLowThreshold(floatscale)
{
cvConvertScale(IdiffF,Iscratch,scale);
cvSub(IavgF,Iscratch,IlowF);
cvSplit(IlowF,Ilow1,Ilow2,Ilow3,0);
}//计算每一个像素的均值和方差观测 (平均绝对差分)
voidcreateModelsfromStats()
{
cvConvertScale(IavgF,IavgF,(double)(1.0/Icount));
cvConvertScale(IdiffF,IdiffF,(double)(1.0/Icount));//make sure diff is always something
cvAddS(IdiffF,cvScalar(1.0,1.0,1.0),IdiffF);
setHighThreshold(7.0);
setLowThreshold(6.0);//对每一帧图像的绝对差大于平均值7倍的像素都认为是前景
}//有了背景模型,同时给出了高低阈值,就可以用它将图像分割成前景(不能被背景模型解释的图像部分)和背景(在背景模型中,任何高低阈值之间的图像部分)
void backgroundDiff(IplImage* I,IplImage*Imask)
{
cvCvtScale(I,Iscratch,1,0); //To float
cvSplit(Iscratch,Igray1,Igray2,Igray3);//channel 1
cvInRange(Igray1,Ilow1,Ihi1,Imask); //是否在高低阈值之间//channel 2
cvInRange(Igray2,Ilow2,Ihi2,Imask);//channel 3
cvInRange(Igray3,Ilow3,Ihi3,Imask);
cvOr(Imask,Imaskt,Imask);//finally , invert the result
cvSubRS(Imask,255,Imask);
}voidDeallocateImages()
{
cvReleaseImage(&IavgF);
cvReleaseImage(&IdiffF);
cvReleaseImage(&IprevF);
cvReleaseImage(&IhiF);
cvReleaseImage(&IlowF);
cvReleaseImage(&Ilow1);
cvReleaseImage(&Ilow2);
cvReleaseImage(&Ilow3);
cvReleaseImage(&Ihi1);
cvReleaseImage(&Ihi2);
cvReleaseImage(&Ihi3);
cvReleaseImage(&Iscratch);
cvReleaseImage(&Iscratch2);
cvReleaseImage(&Igray1);
cvReleaseImage(&Igray2);
cvReleaseImage(&Igray3);
cvReleaseImage(&Imaskt);
}