如何跟踪头部位置

Question

我想做一些类似于Johhny Lee在他的Wii头部追踪中所做的事情 http://www.youtube.com/watch?v=Jd3-eiid-Uw&feature=player_embedded

但我想使用Kinect。由于微软的sdk暴露了骨骼关节，我曾希望我能够用它来获得头部位置。问题是我想用我的台式电脑及其显示器来做这件事。如果我将Kinect传感器放在我的显示器旁边并坐在桌子旁边。几乎只有我的头部和颈部对于传感器是可见的，因此骨骼跟踪不会在我的头部位置上拾取。

是否有人熟悉使用Kinect的头部跟踪项目？最好是在C＃

Answer 1

我认为对于此应用程序，您无法使用任何框架（如Microsoft的SDK或OpenNI）提供的骨架跟踪。

我建议通过对原始深度数据应用深度阈值来对用户的头部进行分段。这应该导致背景减少。我认为已有的方法可以做到这一点。

作为第二步，您希望在分段用户中拥有类似轴的东西。最简单的方法是使用opencv fitEllipse。返回椭圆的主轴与深度信息结合使用，可以得到此轴。

此方法仅在大多数分段点属于用户头时才有效。如果你离得更远，你必须考虑一种只分割头部的方法。椭圆拟合应始终有效。

Answer 2

Windows SDK的官方Kinect存在限制，它与XBox和XDK提供的指导一致，因为您需要距传感器1.2米到3.5米才能使用Kinect传感器。实际上，在OpenNI / NITE库等备用SDK中可以减少此限制，从而可以检测更接近传感器的骨架/对象。

你在skeltal输入时也会遇到的问题是它只会检测头部与骨骼成比例的位置，但如果你将头部左右旋转则不会。为了达到这个目的，你不会使用原始深度流和一些关于物体识别的智能，这有点复杂。

在过去，我使用过这个商业.NET API，它使用网络摄像头来跟踪头部动作，并实现您的目标：http://luxand.com/facesdk/index2.php

Answer 3

您不需要kinect来跟踪您的头部位置。通过使用面部跟踪，您可以使用普通相机和openCV执行相同的操作。

这里显示的简单示例：http://vimeo.com/19464641

在视频中，我使用openCV来跟踪我的脸（你几乎看不到角落，但红点表示我的脸部位置）。

Answer 4

查看关于此类主题的第9频道tutorials。你会去参加Skeletal Fundamentals Video。但如果你想节省时间，这里有一些代码 的 XAML

<Window x:Class="SkeletalTracking.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="MainWindow" Height="600" Width="800" Loaded="Window_Loaded" 
    xmlns:my="clr-namespace:Microsoft.Samples.Kinect.WpfViewers;assembly=Microsoft.Samples.Kinect.WpfViewers" 
    Closing="Window_Closing" WindowState="Maximized">       
<Canvas Name="MainCanvas">
    <my:KinectColorViewer Canvas.Left="0" Canvas.Top="0" Width="640" Height="480" Name="kinectColorViewer1" 
                          Kinect="{Binding ElementName=kinectSensorChooser1, Path=Kinect}" />
    <my:KinectSensorChooser Canvas.Left="250" Canvas.Top="380" Name="kinectSensorChooser1" Width="328" />
    <Image Canvas.Left="66" Canvas.Top="90" Height="87" Name="headImage" Stretch="Fill" Width="84" Source="/SkeletalTracking;component/c4f-color.png" />
</Canvas>

内部代码

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
using Microsoft.Kinect;
using Coding4Fun.Kinect.Wpf; 

namespace SkeletalTracking
{
/// <summary>
/// Interaction logic for MainWindow.xaml
/// </summary>
public partial class MainWindow : Window
{
    public MainWindow()
    {
        InitializeComponent();
    }

    bool closing = false;
    const int skeletonCount = 6; 
    Skeleton[] allSkeletons = new Skeleton[skeletonCount];

    private void Window_Loaded(object sender, RoutedEventArgs e)
    {
        kinectSensorChooser1.KinectSensorChanged += new DependencyPropertyChangedEventHandler(kinectSensorChooser1_KinectSensorChanged);

    }

    void kinectSensorChooser1_KinectSensorChanged(object sender, DependencyPropertyChangedEventArgs e)
    {
        KinectSensor old = (KinectSensor)e.OldValue;

        StopKinect(old);

        KinectSensor sensor = (KinectSensor)e.NewValue;

        if (sensor == null)
        {
            return;
        }




        var parameters = new TransformSmoothParameters
        {
            Smoothing = 0.3f,
            Correction = 0.0f,
            Prediction = 0.0f,
            JitterRadius = 1.0f,
            MaxDeviationRadius = 0.5f
        };
        //sensor.SkeletonStream.Enable(parameters);

        sensor.SkeletonStream.Enable();

        sensor.AllFramesReady += new EventHandler<AllFramesReadyEventArgs>(sensor_AllFramesReady);
        sensor.DepthStream.Enable(DepthImageFormat.Resolution640x480Fps30); 
        sensor.ColorStream.Enable(ColorImageFormat.RgbResolution640x480Fps30);

        try
        {
            sensor.Start();
        }
        catch (System.IO.IOException)
        {
            kinectSensorChooser1.AppConflictOccurred();
        }
    }

    void sensor_AllFramesReady(object sender, AllFramesReadyEventArgs e)
    {
        if (closing)
        {
            return;
        }

        //Get a skeleton
        Skeleton first =  GetFirstSkeleton(e);

        if (first == null)
        {
            return; 
        }



        //set scaled position
        ScalePosition(headImage, first.Joints[JointType.Head]);
        //ScalePosition(leftEllipse, first.Joints[JointType.HandLeft]);
        //ScalePosition(rightEllipse, first.Joints[JointType.HandRight]);

        GetCameraPoint(first, e); 

    }

    void GetCameraPoint(Skeleton first, AllFramesReadyEventArgs e)
    {

        using (DepthImageFrame depth = e.OpenDepthImageFrame())
        {
            if (depth == null ||
                kinectSensorChooser1.Kinect == null)
            {
                return;
            }


            //Map a joint location to a point on the depth map
            //head
            DepthImagePoint headDepthPoint =
                depth.MapFromSkeletonPoint(first.Joints[JointType.Head].Position);
            //left hand
            DepthImagePoint leftDepthPoint =
                depth.MapFromSkeletonPoint(first.Joints[JointType.HandLeft].Position);
            //right hand
            DepthImagePoint rightDepthPoint =
                depth.MapFromSkeletonPoint(first.Joints[JointType.HandRight].Position);


            //Map a depth point to a point on the color image
            //head
            ColorImagePoint headColorPoint =
                depth.MapToColorImagePoint(headDepthPoint.X, headDepthPoint.Y,
                ColorImageFormat.RgbResolution640x480Fps30);
            //left hand
            ColorImagePoint leftColorPoint =
                depth.MapToColorImagePoint(leftDepthPoint.X, leftDepthPoint.Y,
                ColorImageFormat.RgbResolution640x480Fps30);
            //right hand
            ColorImagePoint rightColorPoint =
                depth.MapToColorImagePoint(rightDepthPoint.X, rightDepthPoint.Y,
                ColorImageFormat.RgbResolution640x480Fps30);


            //Set location
            CameraPosition(headImage, headColorPoint);
            //CameraPosition(leftEllipse, leftColorPoint);
            //CameraPosition(rightEllipse, rightColorPoint);
        }        
    }


    Skeleton GetFirstSkeleton(AllFramesReadyEventArgs e)
    {
        using (SkeletonFrame skeletonFrameData = e.OpenSkeletonFrame())
        {
            if (skeletonFrameData == null)
            {
                return null; 
            }


            skeletonFrameData.CopySkeletonDataTo(allSkeletons);

            //get the first tracked skeleton
            Skeleton first = (from s in allSkeletons
                                     where s.TrackingState == SkeletonTrackingState.Tracked
                                     select s).FirstOrDefault();

            return first;

        }
    }

    private void StopKinect(KinectSensor sensor)
    {
        if (sensor != null)
        {
            if (sensor.IsRunning)
            {
                //stop sensor 
                sensor.Stop();

                //stop audio if not null
                if (sensor.AudioSource != null)
                {
                    sensor.AudioSource.Stop();
                }


            }
        }
    }

    private void CameraPosition(FrameworkElement element, ColorImagePoint point)
    {
        //Divide by 2 for width and height so point is right in the middle 
        // instead of in top/left corner
        Canvas.SetLeft(element, point.X - element.Width / 2);
        Canvas.SetTop(element, point.Y - element.Height / 2);

    }

    private void ScalePosition(FrameworkElement element, Joint joint)
    {
        //convert the value to X/Y
        //Joint scaledJoint = joint.ScaleTo(1280, 720); 

        //convert & scale (.3 = means 1/3 of joint distance)
        //Joint scaledJoint = joint.ScaleTo(1280, 720, .3f, .3f);

        Canvas.SetLeft(element, scaledJoint.Position.X);
        Canvas.SetTop(element, scaledJoint.Position.Y); 

    }


    private void Window_Closing(object sender, System.ComponentModel.CancelEventArgs e)
    {
        closing = true; 
        StopKinect(kinectSensorChooser1.Kinect); 
    }



   }
}

我个人会建议观看视频，因为他们会解释所有内容。祝你的项目好运！

Answer 5

我建议将Aforge.net与Microsoft XNA Framework一起使用，或仅使用Aforge.net。你需要自己做一些开发。我也在使用C＃进行类似的事情。我想你将无法找到一个完整的开箱即用的例子。还没有人做过这件事。 （如果我错了，请纠正我。）