Question

与opencv有关C++程序解释问题

cvCvtColor( img, gray, CV_BGR2GRAY );
cvResize( gray, small_img, CV_INTER_LINEAR );
cvEqualizeHist( small_img, small_img );
cvClearMemStorage( storage );
if( cascade )
{
CvSeq* faces = cvHaarDetectObjects( small_img, cascade, storage, 1.1, 2,
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 );

Answer 1

cvCvtColor( img, gray, CV_BGR2GRAY ); //把彩色图像img转化为灰度图像gray
cvResize( gray, small_img, CV_INTER_LINEAR ); //采用线性插值的方法调整gray图像和small_img相匹配
cvEqualizeHist( small_img, small_img ); //对small_img进行直方图均衡化，结果放在small_img
cvClearMemStorage( storage ); //清空storage内存储的内容（但不释放内存）
if( cascade )
{ CvSeq* faces = cvHaarDetectObjects( small_img, cascade, storage, 1.1, 2,cvSize(30, 30) ); //对small_img进行检索，返回的矩形框序列存放在faces
for( int i = 0; i < (faces ? faces->total : 0); i++ )
{ CvRect* r = (CvRect*)cvGetSeqElem( faces, i ); //获取每一个寻找到的物体的矩形框，一共找到faces->total个
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 ); //在img图像内绘制一个圆心为center半径为radius线条颜色为colors[i%8]的圆
} //3 是线的粗细，负数时表示填充，8线类型，0表示小数点位数
}
cvShowImage( "result", img ); //显示图像img