两帧之间的关节速度 [英] velocity of a joint between two frames
问题描述
你好，
我在这个问题上一直在堆叠，我真的很感激，如果有人可以帮助我。
我在许多论坛上多次问过，我搜索了很多，但没有回答真正帮助我。
我正在开发一个应用程序，我必须使用vs c＃2012计算骨骼体关节的速度和kinect sdk 1.7
在问这个问题之前我首先要确定事物的逻辑，
如果我理解正确，delta_time我正在寻找计算速度，不是一帧的持续时间（1 / 30s），但必须从两个时刻计算：
1-检测并保存"关节点"的瞬间。在第一帧中，在检测并保存相同的"关节点"的瞬间，在下一帧中
如果不是这样，感谢您澄清事情。
从这个假设开始，我写了一个代码：
- 检测一个人
- 跟踪脊柱关节==>如果它被跟踪，那么将其坐标保存到列表中（我简化了Y轴上的工作以简化）
- 选择保存坐标的时间
- 增加framecounter（最初等于零）
- 如果帧计数器是> 1 计算速度（x2 - x1）/（T2 - T1）并保存它
这里是一段代码：
System.Diagnostics.Stopwatch stopWatch = new System.Diagnostics.Stopwatch（）;
     双msNow;
     双msPast;
     双差异;
      TimeSpan currentTime;
&NBSP; &NBSP; &NBSP; TimeSpan lastTime = new TimeSpan（0）;&NBSP;列表与LT;双> Sylist = new List< double>（）;
private int framecounter = 0;
private void KinectSensorOnAllFramesReady（object sender，AllFramesReadyEventArgs allFramesReadyEventArgs）
{
Skeleton first = GetFirstSkeleton（allFramesReadyEventArgs）;
if（first == null）//如果没有骨架
{
txtP.Text ="没有人检测到'; //（空闲模式）
return;
}
其他
{
txtP.Text =""检测到某人";
skeletonDetected = true;
///看看这个人是否被完全检测到
find_coordinates（first）;
/ *******************************
*时间计算*
/ ******************************* /
currentTime = stopWatch.Elapsed;
msNow = currentTime.Seconds * 1000 + currentTime.Milliseconds;
if（lastTime.Ticks！= 0）
{
msPast = lastTime.Seconds * 1000 + lastTime.Milliseconds;
diff = msNow - msPast;
}
lastTime = currentTime;
}
// framecounter ++;
}
void find_coordinates（Skeleton first）
{
// *修改07052014 ***** /
联合脊柱= first.Joints [JointType.Spine];
if（Spine.TrackingState == JointTrackingState.Tracked）
{
double Sy = Spine.Position.Y;
/ *******************************
*时间开始*
/ * ****************************** /
stopWatch.Start（）;
Sylist.Add（Sy）;
framecounter ++;
}
其他
返回;
if（framecounter> 1）
{
double delta_Distance = Sylist [Sylist.Count] - Sylist [Sylist.Count - 1];
}
}
<在这种情况下，我真的不知道如何使用时间跨度和秒表（我的意思是当有帧可以处理多次/秒时）
我将感激不尽任何帮助！
DKF
情侣。
1。回顾一下如何获得跟踪骨架。你如何确定你正在使用的骨架是你想要的骨架？
如何在C＃中访问跟踪的骨架数据
http://msdn.microsoft.com/en-us/library/jj131025.aspx
2 。你为什么要用计时器？甚至骨架框架也包含时间戳。这将确保您准确计算帧之间的时差。
http://msdn.microsoft.com/en-us/library/microsoft.kinect.skeletonframe.timestamp.aspx
Hello,
I'm stack for along time in this problem and i will really appreciate if any one could help me in that.
I asked many times in many forums, i've searched alot but no answer that really helped me.
i'm developping an application where i have to calculate the velocity of a joint of skeleton body using vs c# 2012 and kinect sdk 1.7
i have first to be sure of the logic of things before asking this question so,
if I understood correctly, the delta_time i'm looking for to calculate velocity, is not the duration of one frame (1/30s) but it must be calculated from two instants:
1- the instant when detecting and saving the "joint point" in the first frame
2- the instant when detecting and saving the same "joint point" in the next frame
if it's not true, thank you for clarifying things.
starting from this hypothesis, i wrote a code to :
- detectiong a person
- tracking the spine joint ==> if it's is tracked then saving its coordinates into a list (I reduced the work for the moment on the Y axis to simplify)
- pick up the time when saving the coordinates
- increment the framecounter (initially equal to zero)
- if the frame counter is > 1 calculate velocity ( x2 - x1)/(T2 - T1) and save it
here is a piece of the code:
System.Diagnostics.Stopwatch stopWatch = new System.Diagnostics.Stopwatch();
double msNow;
double msPast;
double diff;
TimeSpan currentTime;
TimeSpan lastTime = new TimeSpan(0);List<double> Sylist = new List<double>();
private int framecounter = 0;
private void KinectSensorOnAllFramesReady(object sender, AllFramesReadyEventArgs allFramesReadyEventArgs) { Skeleton first = GetFirstSkeleton(allFramesReadyEventArgs); if (first == null) // if there is no skeleton { txtP.Text = "No person detected"; // (Idle mode) return; } else { txtP.Text = "A person is detected"; skeletonDetected = true; /// look if the person is totally detected find_coordinates(first); /******************************* * time computing * /*******************************/ currentTime = stopWatch.Elapsed; msNow = currentTime.Seconds * 1000 + currentTime.Milliseconds; if (lastTime.Ticks != 0) { msPast = lastTime.Seconds * 1000 + lastTime.Milliseconds; diff = msNow - msPast; } lastTime = currentTime; } //framecounter++; } void find_coordinates(Skeleton first) { //*modification 07052014 *****/ Joint Spine = first.Joints[JointType.Spine]; if (Spine.TrackingState == JointTrackingState.Tracked) { double Sy = Spine.Position.Y; /******************************* * time starting * /*******************************/ stopWatch.Start(); Sylist.Add(Sy); framecounter++; } else return; if (framecounter > 1) { double delta_Distance = Sylist[Sylist.Count] - Sylist[Sylist.Count - 1]; } }
to be honnest, i dont really know how ti use timespan and stopwatch in this context ( i mean when there are frames to process many times/s)
i will be thankfull for any help !
DKF
Couples of things.
1. review how you get a tracked skeleton. How are you determining the skeleton you are using is the one you want?
How to access tracked skeleton data in C#
http://msdn.microsoft.com/en-us/library/jj131025.aspx2. why are you using a timer? Even skeleton frame contains a timestamp. This will ensure you are accurately calculating the time difference between frames.
http://msdn.microsoft.com/en-us/library/microsoft.kinect.skeletonframe.timestamp.aspx
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