Question

我正在使用KinectContrib提供的F＃骨架跟踪模板。 C＃中的模板做同样的事情，所以我知道硬件没问题。

该程序将在极少数情况下跟踪一次，但没有一致的模式。自从昨晚以来我一直在玩代码，所以我正在寻找某人在另一个系统上确认相同的行为或者有关如何更改代码的指示。

提前致谢。

这是模板代码：

#light

open System
open System.Windows
open System.Windows.Media.Imaging
open Microsoft.Kinect
open System.Diagnostics

let sensor = KinectSensor.KinectSensors.[0]

//The main canvas that is handling the ellipses
let canvas = new System.Windows.Controls.Canvas()
canvas.Background <- System.Windows.Media.Brushes.Transparent

let ds : byte = Convert.ToByte(1)
let dummySkeleton : Skeleton = new Skeleton(TrackingState = SkeletonTrackingState.Tracked)

// Thanks to Richard Minerich (@rickasaurus) for helping me figure out
// some array concepts in F#.
let mutable pixelData : byte array = [| |]
let mutable skeletons : Skeleton array = [| |]

//Right hand ellipse
let rhEllipse = new System.Windows.Shapes.Ellipse()
rhEllipse.Height <- 20.0
rhEllipse.Width <- 20.0
rhEllipse.Fill <- System.Windows.Media.Brushes.Red
rhEllipse.Stroke <- System.Windows.Media.Brushes.White

//Left hand ellipse
let lhEllipse = new System.Windows.Shapes.Ellipse()
lhEllipse.Height <- 20.0
lhEllipse.Width <- 20.0
lhEllipse.Fill <- System.Windows.Media.Brushes.Red
lhEllipse.Stroke <- System.Windows.Media.Brushes.White

//Head ellipse
let hEllipse = new System.Windows.Shapes.Ellipse()
hEllipse.Height <- 20.0
hEllipse.Width <- 20.0
hEllipse.Fill <- System.Windows.Media.Brushes.Red
hEllipse.Stroke <- System.Windows.Media.Brushes.White

canvas.Children.Add(rhEllipse) |> ignore
canvas.Children.Add(lhEllipse) |> ignore
canvas.Children.Add(hEllipse) |> ignore

let grid = new System.Windows.Controls.Grid()

let winImage = new System.Windows.Controls.Image()
winImage.Height <- 600.0
winImage.Width <- 800.0

grid.Children.Add(winImage) |> ignore
grid.Children.Add(canvas) |> ignore

//Video frame is ready to be processed.
let VideoFrameReady (sender : obj) (args: ColorImageFrameReadyEventArgs) = 
    let receivedData = ref false

    using (args.OpenColorImageFrame()) (fun r -> 
        if (r <> null) then
            (
                pixelData <- Array.create r.PixelDataLength ds
                //Array.Resize(ref pixelData, r.PixelDataLength)
                r.CopyPixelDataTo(pixelData)
                receivedData := true
        )

        if (receivedData <> ref false) then
            (
        winImage.Source <- BitmapSource.Create(640, 480, 96.0, 96.0, Media.PixelFormats.Bgr32, null, pixelData, 640 * 4)
    )
    )

//Required to correlate the skeleton data to the PC screen
//IMPORTANT NOTE: Code for vector scaling was imported from the Coding4Fun Kinect Toolkit
//available here: http://c4fkinect.codeplex.com/
//I only used this part to avoid adding an extra reference.
let ScaleVector (length : float32, position : float32)  =
    let value = (((length / 1.0f) / 2.0f) * position) + (length / 2.0f)
    if value > length then
        length
    elif value < 0.0f then
        0.0f
    else
        value

//This will set the ellipse positions depending on the passed instance and joint
let SetEllipsePosition (ellipse : System.Windows.Shapes.Ellipse, joint : Joint) =
    let vector = new Microsoft.Kinect.SkeletonPoint(X = ScaleVector(640.0f, joint.Position.X), Y=ScaleVector(480.0f, -joint.Position.Y),Z=joint.Position.Z)
    let mutable uJoint = joint
    uJoint.TrackingState <- JointTrackingState.Tracked
    uJoint.Position <- vector

    System.Windows.Controls.Canvas.SetLeft(ellipse,(float uJoint.Position.X))
    System.Windows.Controls.Canvas.SetTop(ellipse,(float uJoint.Position.Y))

//Triggered when a new skeleton frame is ready for processing
let SkeletonFrameReady (sender : obj) (args: SkeletonFrameReadyEventArgs) = 
    let receivedData = ref false

    using (args.OpenSkeletonFrame()) (fun r -> 
        if (r <> null) then
            (
                skeletons <- Array.create r.SkeletonArrayLength dummySkeleton
                r.CopySkeletonDataTo(skeletons)

                for i in skeletons do
                    Debug.WriteLine(i.TrackingState.ToString())

                receivedData := true
        )

        if (receivedData <> ref false) then
            (
                for i in skeletons do
                    if i.TrackingState <> SkeletonTrackingState.NotTracked then
                        (
                        let currentSkeleton = i

                        SetEllipsePosition(hEllipse, currentSkeleton.Joints.[JointType.Head])
                        SetEllipsePosition(lhEllipse, currentSkeleton.Joints.[JointType.HandLeft])
                        SetEllipsePosition(rhEllipse, currentSkeleton.Joints.[JointType.HandRight])
                   )
        )
        )


let WindowLoaded (sender : obj) (args: RoutedEventArgs) = 
    sensor.Start()
    sensor.ColorStream.Enable()
    sensor.SkeletonStream.Enable()
    sensor.ColorFrameReady.AddHandler(new EventHandler<ColorImageFrameReadyEventArgs>(VideoFrameReady))
    sensor.SkeletonFrameReady.AddHandler(new EventHandler<SkeletonFrameReadyEventArgs>(SkeletonFrameReady))

let WindowUnloaded (sender : obj) (args: RoutedEventArgs) = 
    sensor.Stop()

//Defining the structure of the test window
let window = new Window()
window.Width <- 800.0
window.Height <- 600.0
window.Title <- "Kinect Skeleton Application"
window.Loaded.AddHandler(new RoutedEventHandler(WindowLoaded))
window.Unloaded.AddHandler(new RoutedEventHandler(WindowUnloaded))
window.Content <- grid
window.Show()

[<STAThread()>]
do 
    let app = new Application() in
    app.Run(window) |> ignore

Answer 1

我最终根据这篇文章http://channel9.msdn.com/coding4fun/kinect/Kinecting-with-F重写了它，骨架跟踪现在正在运行。仍然对原始代码不能正常工作的原因感兴趣。

// Learn more about F# at http://fsharp.net
#light

open System
open System.Windows
open System.Windows.Media.Imaging
open System.Windows.Threading
open Microsoft.Kinect
open System.Diagnostics

[<STAThread>]
do
    let sensor = KinectSensor.KinectSensors.[0]
    sensor.SkeletonStream.Enable()
    sensor.Start()

    // Set-up the WPF window and its contents
    let width = 1024.
    let height = 768.
    let w = Window(Width=width, Height=height)
    let g = Controls.Grid()
    let c = Controls.Canvas()
    let hd = Shapes.Rectangle(Fill=Media.Brushes.Red, Width=15., Height=15.)
    let rh = Shapes.Rectangle(Fill=Media.Brushes.Blue, Width=15., Height=15.)
    let lh = Shapes.Rectangle(Fill=Media.Brushes.Green, Width=15., Height=15.)
    ignore <| c.Children.Add hd
    ignore <| c.Children.Add rh
    ignore <| c.Children.Add lh
    ignore <| g.Children.Add c
    w.Content <- g

    w.Unloaded.Add(fun args -> sensor.Stop())

    let getDisplayPosition w h (joint : Joint) =
        let x = ((w * (float)joint.Position.X + 2.0) / 4.0) + (w/2.0)
        let y = ((h * -(float)joint.Position.Y + 2.0) / 4.0) + (h/2.0)
        System.Console.WriteLine("X:" + x.ToString() + " Y:" + y.ToString())
        new Point(x,y)

    let draw (joint : Joint) (sh : System.Windows.Shapes.Shape) =
        let p = getDisplayPosition width height joint
        sh.Dispatcher.Invoke(DispatcherPriority.Render, Action(fun () -> System.Windows.Controls.Canvas.SetLeft(sh, p.X))) |> ignore
        sh.Dispatcher.Invoke(DispatcherPriority.Render, Action(fun () -> System.Windows.Controls.Canvas.SetTop(sh, p.Y))) |> ignore

    let drawJoints (sk : Skeleton) =
        draw (sk.Joints.Item(JointType.Head)) hd
        draw (sk.Joints.Item(JointType.WristRight)) rh
        draw (sk.Joints.Item(JointType.WristLeft)) lh

    let skeleton (sensor : KinectSensor) =
        let rec loop () =
            async {
                let! args = Async.AwaitEvent sensor.SkeletonFrameReady
                use frame = args.OpenSkeletonFrame()
                let skeletons : Skeleton[] = Array.zeroCreate(frame.SkeletonArrayLength)
                frame.CopySkeletonDataTo(skeletons)
                skeletons 
                |> Seq.filter (fun s -> s.TrackingState <> SkeletonTrackingState.NotTracked)
                |> Seq.iter  (fun s ->  drawJoints s)
                return! loop ()
            }
        loop ()

    skeleton sensor |> Async.Start

    let a = Application()
    ignore <| a.Run(w)

Answer 2

在F＃中，您在模块本身内声明的任何值绑定（例如，let或do）将在第一次打开模块或从另一个模块访问时执行。如果您熟悉C＃，可以将这些值绑定视为在类型构造函数（即static构造函数）中执行。

我怀疑代码的第二个版本有效但不是第一个版本的原因是，在第二个版本中，您正在创建Window并从运行该代码的STA线程中将形状绘制到其中应用程序的消息循环。在第一个版本中，我猜测代码正在某个其他线程上执行，这就是为什么它没有按预期工作。

您的代码的第二个版本没有任何问题，但更典型的F＃方法是将您的功能（getDisplayPosition，draw等）提升到顶级{ {1}}绑定。通过明确表明这些函数没有捕获do中创建的任何本地值，这使得代码更容易阅读。

F＃中的Kinect骨架跟踪问题

2 个答案: