How can I detect human body outline using OpenCV? - ios

Question

I am developing a small demo with openCV which can detect the body with real time camera.
Currently My app detect the face successfully. So, My question is, How I can detect the human body like face detection.
Here is my Code (which is called at every frame):-
///1. Convert input UIImage to Mat
std::vector<cv::Rect> faces;
CGImageRef image = CGImageCreateCopy(source.CGImage);
CGFloat cols = CGImageGetWidth(image);
CGFloat rows = CGImageGetHeight(image);
cv::Mat frame(rows, cols, CV_8UC4);
CGBitmapInfo bitmapFlags = kCGImageAlphaNoneSkipLast | kCGBitmapByteOrderDefault;
size_t bitsPerComponent = 8;
size_t bytesPerRow = frame.step[0];
CGColorSpaceRef colorSpace = CGImageGetColorSpace(image);
CGContextRef context = CGBitmapContextCreate(frame.data, cols, rows, bitsPerComponent, bytesPerRow, colorSpace, bitmapFlags);
CGContextDrawImage(context, CGRectMake(0.0f, 0.0f, cols, rows), image);
CGContextRelease(context);
cv::Mat frame_gray;
cvtColor( frame, frame_gray, CV_BGR2GRAY );
equalizeHist( frame_gray, frame_gray );
///2. detection
NSString *eyes_cascade_name = [[NSBundle mainBundle] pathForResource:#"haarcascade_eye" ofType:#"xml"];
NSString *face_cascade_name = [[NSBundle mainBundle] pathForResource:#"haarcascade_frontalface_default" ofType:#"xml"];
if(!cascade_loaded){
std::cout<<"loading ..";
if( !eyes_cascade.load( std::string([eyes_cascade_name UTF8String]) ) ){ printf("--(!)Error loading\n"); return source;};
if( !face_cascade.load( std::string([face_cascade_name UTF8String]) ) ){ printf("--(!)Error loading\n"); return source;};
cascade_loaded = true;
}
face_cascade.detectMultiScale(frame_gray, faces, 1.3, 5, CV_HAAR_SCALE_IMAGE);
for( size_t i = 0; i < faces.size(); i++ )
{
cv::Point center( faces[i].x + faces[i].width*0.5, faces[i].y + faces[i].height*0.5 );
ellipse( frame, center, cv::Size( faces[i].width*0.5, faces[i].height*0.5), 0, 0, 360, cv::Scalar( 0, 100, 255 ), 4, 8, 0 );
cv::Mat faceROI = frame_gray( faces[i] );
std::vector<cv::Rect> eyes;
//-- In each face, detect eyes
eyes_cascade.detectMultiScale( faceROI, eyes, 1.1, 2, 0 |CV_HAAR_SCALE_IMAGE, cv::Size(30, 30) );
for( size_t j = 0; j < eyes.size(); j++ )
{
cv::Point center( faces[i].x + eyes[j].x + eyes[j].width*0.5, faces[i].y + eyes[j].y + eyes[j].height*0.5 );
int radius = cvRound( (eyes[j].width + eyes[j].height)*0.25 );
circle( frame, center, radius, cv::Scalar( 5, 255, 0 ), 2, 8, 0 );
}
}