face.m

#import <stdio.h>
#import <highgui.h>
#import <cv.h>

IplImage *renderFaces(IplImage *, CvSeq *, double);

int main(int argc, char** argv)
{
    double scale = 5; // primary speed factor

    CvHaarClassifierCascade* cascade =
        (CvHaarClassifierCascade*) cvLoad( "haarcascade_frontalface_alt.xml"
                                         , 0, 0, 0);
    CvMemStorage* storage = cvCreateMemStorage(0);

    CvCapture *capture = cvCreateCameraCapture(0);
    IplImage *frame = cvQueryFrame(capture);
    IplImage *frameCopy = cvCreateImage( cvGetSize(frame)
                                       , IPL_DEPTH_8U
                                       , frame->nChannels);
    IplImage *gray = cvCreateImage(cvGetSize(frameCopy), 8, 1);
    IplImage *smallImg = cvCreateImage(cvSize( cvRound(frameCopy->width/scale)
                                             , cvRound(frameCopy->height/scale)
                                             ), 8, 1);

    cvNamedWindow("result", 1);

    while(1) {
        frame = cvQueryFrame(capture);
        cvCopy(frame, frameCopy, 0);

        cvCvtColor(frameCopy, gray, CV_BGR2GRAY);
        cvResize(gray, smallImg, CV_INTER_LINEAR);
        cvEqualizeHist(smallImg, smallImg);
        cvClearMemStorage(storage);

        double t = (double)cvGetTickCount();
        CvSeq* faces = cvHaarDetectObjects( smallImg, cascade, storage,
                                            1.1, 2, 0
                                            //|CV_HAAR_FIND_BIGGEST_OBJECT
                                            //|CV_HAAR_DO_ROUGH_SEARCH
                                            |CV_HAAR_DO_CANNY_PRUNING
                                            //|CV_HAAR_SCALE_IMAGE
                                            ,
                                            cvSize(30, 30), cvSize(0, 0));
        t = (double)cvGetTickCount() - t;
        printf("detection time = %gms\n", t/((double)cvGetTickFrequency()*1000.));

        frameCopy = renderFaces(frameCopy, faces, scale);
        cvShowImage("result", frameCopy);

        if(cvWaitKey(5) == 27) {
            cvReleaseImage(&frameCopy);
            cvReleaseImage(&gray);
            cvReleaseImage(&smallImg);
            cvReleaseCapture(&capture);
            cvDestroyWindow("result");
            return 0;
        }
    }
}

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}}
};

IplImage *renderFaces(IplImage *img, CvSeq *faces, double scale)
{
    int i; for(i = 0; i < (faces ? faces->total : 0); i++) {
        CvRect* r = (CvRect*)cvGetSeqElem(faces, i);
        CvMat smallImg_roi;
        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);
    }
    return img;
}