problem with face detection

Bitmap imgs = (Bitmap)pictureBox1.Image.Clone();
Image<Bgr, Byte> currentframe = new Image<Bgr, byte>(imgs);
// Image<Bgr, Byte> currentframe = new Image<Bgr, byte>("D://bs//image processing//image processing//images//3.jpg");

String facefile = "haarcascade_frontalface_default.xml";
using (HaarCascade face = new HaarCascade(facefile))
{
    using (Image<Gray, Byte> grey = currentframe.Convert<Gray, Byte>())
    {
        grey._EqualizeHist();
        MCvAvgComp[] facedetected = face.Detect(grey, 1.1, 10, Emgu.CV.CvEnum.HAAR_DETECTION_TYPE.DO_CANNY_PRUNING, new Size(20, 20));
        foreach (MCvAvgComp f in facedetected)
        {
            currentframe.Draw(f.rect, new Bgr(Color.Blue), 2);
            grey.ROI = f.rect;
        }
    }


}

//  ImageViewer.Show(currentframe);
pictureBox1.Image = currentframe.ToBitmap();

// MessageBox.Show("successfully image drawed");