Face detection

From Emgu CV: OpenCV in .NET (C#, VB, C++ and more)
Jump to: navigation, search

This tutorial was extracted from this link.


Notes in order to run this example:

  • Create a Windows Form Application
    • Add a PictureBox and a Timer (and Enable it)
  • Run it on a x86 system
  • Be sure you have the OpenCV relevant dlls (included with the Emgu CV download) in the folder where you code executes.
  • Adjust the path to find the Haarcascade xml (last line of the code)


<source lang="csharp"> using System; using System.Windows.Forms; using System.Drawing; using Emgu.CV; using Emgu.Util; using Emgu.CV.Structure; using Emgu.CV.CvEnum;

namespace opencvtut {

   public partial class Form1 : Form
   {
               private Capture cap;
               private HaarCascade haar;
       public Form1()
       {
           InitializeComponent();
       }
       private void timer1_Tick(object sender, EventArgs e)
       {
               using (Image<Bgr, byte> nextFrame = cap.QueryFrame())
               {
                       if (nextFrame != null)
                       {
                               // there's only one channel (greyscale), hence the zero index
                               //var faces = nextFrame.DetectHaarCascade(haar)[0];
                               Image<Gray, byte> grayframe = nextFrame.Convert<Gray, byte>();
                               var faces =
                                       grayframe.DetectHaarCascade(
                                               haar, 1.4, 4,
                                               HAAR_DETECTION_TYPE.DO_CANNY_PRUNING,
                                               new Size(nextFrame.Width/8, nextFrame.Height/8)
                                               )[0];
                               foreach (var face in faces)
                               {
                                       nextFrame.Draw(face.rect, new Bgr(0,double.MaxValue,0), 3);
                               }
                               pictureBox1.Image = nextFrame.ToBitmap();
                       }
               }
       }
       private void Form1_Load(object sender, EventArgs e)
       {
           // passing 0 gets zeroth webcam
                       cap = new Capture(0);
           // adjust path to find your xml
                       haar = new HaarCascade(
               "..\\..\\..\\..\\lib\\haarcascade_frontalface_alt2.xml");
       }
   }

}