Question

I’m trying to display Kinect’s video stream into PictureBox. The reason is, I’d like to overlay it with some images and use FillEllipse() method to add real time markers.
However, I ended up with a box with a red x (cross) in it. Could someone show me, where did I go wrong? Should I use WritableBitmap instead? I had a thought of this, but Writeable bitmap does not offer method such as FillEllipse() to place markers.

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Linq;
using System.Text;
using System.Windows.Forms;

using Microsoft.Kinect;
using System.Drawing.Imaging;
using System.Drawing;
using System.Runtime.InteropServices;

namespace fTrack_WF
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        KinectSensor myKinect;

        private void Window_Loaded(object sender, EventArgs e)
        {
            if (KinectSensor.KinectSensors.Count == 0)
            {
                MessageBox.Show("No Kinects device detected", "Camera View");
                Application.Exit();
                return;
            }

            try
            {
                // get first Kinect device attached on computer
                myKinect = KinectSensor.KinectSensors[0];

                // enable depth stream
                myKinect.DepthStream.Enable();

                // enable color video stream
                myKinect.ColorStream.Enable();

                // start the sensor
                myKinect.Start();


                // connect up the video event handler
                myKinect.ColorFrameReady += new EventHandler<ColorImageFrameReadyEventArgs>(myKinect_ColorFrameReady);

            }
            catch
            {
                MessageBox.Show("Kinect initialise failed", "Camera viewer");
                Application.Exit();
            }


        }


        #region Video Image Processing

        byte[] colorData = null;
        Bitmap kinectVideoBitmap = null;
        IntPtr colorPtr;

        void myKinect_ColorFrameReady(object sender, ColorImageFrameReadyEventArgs e)
        {
            using (ColorImageFrame colorFrame = e.OpenColorImageFrame())
            {
                if (colorFrame == null) return;

                if (colorData == null)
                    colorData = new byte[colorFrame.PixelDataLength];

                colorFrame.CopyPixelDataTo(colorData);

                Marshal.FreeHGlobal(colorPtr);
                colorPtr = Marshal.AllocHGlobal(colorData.Length);
                Marshal.Copy(colorData, 0, colorPtr, colorData.Length);

                kinectVideoBitmap = new Bitmap(
                    colorFrame.Width,
                    colorFrame.Height,
                    colorFrame.Width * colorFrame.BytesPerPixel;
                    PixelFormat.Format32bppRgb,
                    colorPtr);

                kinectVideoBox.Image = kinectVideoBitmap;

                kinectVideoBitmap.Dispose();

            }

        }

        #endregion
    }
}

Thank you very much!

Regards,
ikel

Answer 1

I found the answer. Dispose is necessary to free up resources as indicated here. The problem was, I disposed too early after drawing it, and so it appeared as if nothing was drawn. However, the clearer answer, to me anyway, was given here.

Bitmap inherits from Image, which implements IDisposable, so when
you’re done using an instance, you should call Dispose() on it. This
will clean up the unmanaged resource in Image.

However, Image also implements a finalizer, so if for some reason you
cannot call Dispose(), the resource will be reclaimed during
finalization of the instance, which will happen at some point after
the instance is no longer referenced.

I simply removed kinectVideoBitmap.Dispose(); and my Windows Forms displays Kinect’s video stream inside PictureBox control.

Regards,
ikel