转自：http://www.cnblogs.com/yangecnu/archive/2012/04/04/KinectSDK_Depth_Image_Processing_Part1.html
深度数据是Kinect传感器的精髓
DepthImageStream的使用和ColorImageStream的使用类似。DepthImageStream和ColorImageStream都继承自ImageStream。可以像从ColorImageStream获取数据生成图像那样生成景深图像。
显示深度数据的套路相同
初始化
private void InitializeKinectSensor(KinectSensor kinectSensor)
{
if (kinectSensor != null)
{
DepthImageStream depthStream = kinectSensor.DepthStream;
depthStream.Enable(); depthImageBitMap = new WriteableBitmap(depthStream.FrameWidth, depthStream.FrameHeight, , ,
PixelFormats.Gray16, null);
depthImageBitmapRect = new Int32Rect(, , depthStream.FrameWidth, depthStream.FrameHeight);
depthImageStride = depthStream.FrameWidth * depthStream.FrameBytesPerPixel; DepthImage.Source = depthImageBitMap;
kinectSensor.DepthFrameReady += new EventHandler<DepthImageFrameReadyEventArgs>(kinectSensor_DepthFrameReady);
kinectSensor.Start();
}
}
事件处理
void kinectSensor_DepthFrameReady(object sender, DepthImageFrameReadyEventArgs e)
{
if (lastDepthFrame != null)
{
lastDepthFrame.Dispose();
lastDepthFrame = null;
}
lastDepthFrame = e.OpenDepthImageFrame();
if (lastDepthFrame != null)
{
depthPixelDate = new short[lastDepthFrame.PixelDataLength];
lastDepthFrame.CopyPixelDataTo(depthPixelDate);
depthImageBitMap.WritePixels(depthImageBitmapRect, depthPixelDate, depthImageStride, ); CreateColorDepthImage(this.lastDepthFrame, depthPixelDate);
}
}
获取单点深度信息
获取每一个像素的距离很容易，但是要直接使用还需要做一些位操作。可能大家在实际编程中很少情况会用到位运算。如上图所示，深度值存储在第3至15位中，要获取能够直接使用的深度数据需要向右移位，将游戏者索引(Player Index)位移除。后面将会介绍游戏者索引位的重要性。下面的代码简要描述了如何获取像素的深度值。代码中pixelData变量就是从深度帧数据中获取的short数组。PixelIndex基于待计算像素的位置就算出来的。SDK在DepthImageFrame类中定义了一个常量PlayerIndexBitmaskWidth，它定义了要获取深度数据值需要向右移动的位数。
有一点值得注意的是，在UI界面中Image空间的属性中，宽度和高度是硬编码的。如果不设置值，那么空间会随着父容器（From窗体）的大小进行缩放，如果空间的长宽尺寸和深度数据帧的尺寸不一致，当鼠标点击图片时，代码就会返回错误的数据，在某些情况下甚至会抛出异常。像素数组中的数据是固定大小的，它是根据DepthImageStream的Enable方法中的DepthImageFormat参数值来确定的。如果不设置图像控件的大小，那么他就会根据Form窗体的大小进行缩放，这样就需要进行额外的计算，将鼠标的在Form中的位置换算到深度数据帧的维度上。这种缩放和空间转换操作很常见，在后面的文章中我们将会进行讨论，现在为了简单，对图像控件的尺寸进行硬编码。
private void DepthImage_MouseLeftButtonUp(object sender, MouseButtonEventArgs e)
{
// 获取鼠标位置的深度数据
Point p = e.GetPosition(DepthImage);
if (depthPixelDate != null && depthPixelDate.Length > )
{
Int32 pixelIndex = (Int32)(p.X + ((Int32)p.Y * this.lastDepthFrame.Width));
Int32 depth = this.depthPixelDate[pixelIndex] >> DepthImageFrame.PlayerIndexBitmaskWidth; // 获取深度
Int32 depthInches = (Int32)(depth * 0.0393700787); // 英寸
Int32 depthFt = depthInches / ; // 英尺
depthInches = depthInches % ;
//PixelDepth.Text = String.Format("{0}mm~{1}'{1}", depth, depthFt, depthInches);
}
}
深度图像增强
代码中过滤掉了一些距离太近的点。因为过近的点和过远的点都不准确。所以过滤掉了大于3.5米小于0米的数据，将这些数据设置为白色。
private void CreateLighterShadesOfGray(DepthImageFrame depthFrame, short[] pixelData)
{
// 对深度图像的简单处理 —— 高低阈值
Int32 depth;
Int32 loThreashold = ;
Int32 hiThreshold = ;
short[] enhPixelData = new short[depthFrame.Width * depthFrame.Height];
for (int i = ; i < pixelData.Length; i++)
{
depth = pixelData[i] >> DepthImageFrame.PlayerIndexBitmaskWidth;
if (depth < loThreashold || depth > hiThreshold)
{
enhPixelData[i] = 0xFF;
}
else
{
enhPixelData[i] = (short)~pixelData[i];
} }
EnhancedDepthImage.Source = BitmapSource.Create(depthFrame.Width, depthFrame.Height, , , PixelFormats.Gray16, null, enhPixelData, depthFrame.Width * depthFrame.BytesPerPixel);
}
如果能够将16位的灰度级用32位彩色表示效果会更好。当 RGB值一样时，就会呈现出灰色。灰度值的范围是0~255，0为黑色，255为白色，之间的颜色为灰色。现在将灰色值以RGB模式展现出来。
将彩色影像的格式改为了Bgr32位，这意味每一个像素占用32位（4个字节）。每一个R,G,B分别占8位，剩余8位留用。这种模式限制了RGB的取值为0-255，所以需要将深度值转换到这一个范围内。除此之外，我们还设置了最小最大的探测范围，这个和之前的一样，任何不在范围内的都设置为白色。将深度值除以4095（0XFFF，深度探测的最大值），然后乘以255，这样就可以将深度数据转换到0至255之间了。
private void CreateBetterShadesOfGray(DepthImageFrame depthFrame, short[] pixelData)
{
Int32 depth;
Int32 gray;
Int32 loThreashold = ;
Int32 bytePerPixel = ;
Int32 hiThreshold = ;
byte[] enhPixelData = new byte[depthFrame.Width * depthFrame.Height * bytePerPixel];
for (int i = , j = ; i < pixelData.Length; i++, j += bytePerPixel)
{
depth = pixelData[i] >> DepthImageFrame.PlayerIndexBitmaskWidth;
if (depth < loThreashold || depth > hiThreshold)
{
gray = 0xFF;
}
else
{
gray = ( * depth / 0xFFF);
}
enhPixelData[j] = (byte)gray;
enhPixelData[j + ] = (byte)gray;
enhPixelData[j + ] = (byte)gray; }
EnhancedDepthImage.Source = BitmapSource.Create(depthFrame.Width, depthFrame.Height, , , PixelFormats.Bgr32, null, enhPixelData, depthFrame.Width * bytePerPixel);
}
深度数据的彩色渲染 —— 伪彩色图像
将深度数据值转化到0-255并用RGB模式进行显示可以起到增强图像的效果，能够从图像上直观的看出更多的深度细节信息。还有另外一种简单，效果也不错的方法，那就是将深度数据值转换为色调和饱和度并用图像予以显示。
private void CreateColorDepthImage(DepthImageFrame depthFrame, short[] pixelData)
{
Int32 depth;
Double hue;
Int32 loThreshold = ;
Int32 hiThreshold = ;
Int32 bytesPerPixel = ;
byte[] rgb = new byte[];
byte[] enhPixelData = new byte[depthFrame.Width * depthFrame.Height * bytesPerPixel]; for (int i = , j = ; i < pixelData.Length; i++, j += bytesPerPixel)
{
depth = pixelData[i] >> DepthImageFrame.PlayerIndexBitmaskWidth; if (depth < loThreshold || depth > hiThreshold)
{
enhPixelData[j] = 0x00;
enhPixelData[j + ] = 0x00;
enhPixelData[j + ] = 0x00;
}
else
{
hue = (( * depth / 0xFFF) + loThreshold);
ConvertHslToRgb(hue, , , rgb); enhPixelData[j] = rgb[]; //Blue
enhPixelData[j + ] = rgb[]; //Green
enhPixelData[j + ] = rgb[]; //Red
}
} EnhancedDepthImage.Source = BitmapSource.Create(depthFrame.Width, depthFrame.Height, , , PixelFormats.Bgr32, null, enhPixelData, depthFrame.Width * bytesPerPixel);
}
以上代码中使用了ConvertHslToRgb这一函数，该函数的作用是进行两个颜色空间的转换，就是将H(Hue色调)S(Saturation饱和度)L(Light亮度)颜色空间转换到RGB颜色空间的函数。
public void ConvertHslToRgb(double hue, double saturation, double lightness, byte[] rgb)
{
double red = 0.0;
double green = 0.0;
double blue = 0.0;
hue = hue % 360.0;
saturation = saturation / 100.0;
lightness = lightness / 100.0; if (saturation == 0.0)
{
red = lightness;
green = lightness;
blue = lightness;
}
else
{
double huePrime = hue / 60.0;
int x = (int)huePrime;
double xPrime = huePrime - (double)x;
double L0 = lightness * (1.0 - saturation);
double L1 = lightness * (1.0 - (saturation * xPrime));
double L2 = lightness * (1.0 - (saturation * (1.0 - xPrime))); switch (x)
{
case :
red = lightness;
green = L2;
blue = L0;
break;
case :
red = L1;
green = lightness;
blue = L0;
break;
case :
red = L0;
green = lightness;
blue = L2;
break;
case :
red = L0;
green = L1;
blue = lightness;
break;
case :
red = L2;
green = L0;
blue = lightness;
break;
case :
red = lightness;
green = L0;
blue = L1;
break;
}
} rgb[] = (byte)(255.0 * red);
rgb[] = (byte)(255.0 * green);
rgb[] = (byte)(255.0 * blue);
}
}
貌似上面的颜色空间转换挺麻烦的 ~~ 好了，差不多看懂了，自己实现一下：
namespace TestDepthProcess
{ /// <summary>
/// MainWindow.xaml 的交互逻辑
/// </summary>
public partial class MainWindow : Window
{
private KinectSensor kinect;
private WriteableBitmap depthImageBitMap;
private Int32Rect depthImageBitmapRect;
private Int32 depthImageStride;
private DepthImageFrame lastDepthFrame;
private short[] depthPixelDate; public KinectSensor Kinect
{
// C#的set ，get方法好奇葩的说
get { return kinect; }
set
{
if (kinect != null)
{
UninitializeKinectSensor(this.kinect);
kinect = null;
} if (value!=null && value.Status==KinectStatus.Connected)
{
kinect = value;
InitializeKinectSensor(this.kinect);
}
}
} public MainWindow()
{
InitializeComponent();
this.Loaded += (s, e) => DiscoverKinectSensor();
this.Unloaded += (s, e) => this.kinect = null;
} private void UninitializeKinectSensor(KinectSensor kinect)
{
if (kinect!=null)
{
kinect.Stop();
kinect.DepthFrameReady -= new EventHandler<DepthImageFrameReadyEventArgs>(kinectSensor_DepthFrameReady); }
} private void InitializeKinectSensor(KinectSensor kinect)
{
if (kinect!=null)
{
DepthImageStream depthStream = kinect.DepthStream;
depthStream.Enable(); depthImageBitMap = new WriteableBitmap(depthStream.FrameWidth, depthStream.FrameHeight, , , PixelFormats.Gray16, null);
depthImageBitmapRect = new Int32Rect(, , depthStream.FrameWidth, depthStream.FrameHeight);
depthImageStride = depthStream.FrameWidth * depthStream.FrameBytesPerPixel; DepthImage.Source = depthImageBitMap;
kinect.DepthFrameReady += new EventHandler<DepthImageFrameReadyEventArgs>(kinectSensor_DepthFrameReady);
kinect.Start();
}
} private void DiscoverKinectSensor()
{
KinectSensor.KinectSensors.StatusChanged += new EventHandler<StatusChangedEventArgs>(KinectSensors_StatusChanged);
this.Kinect = KinectSensor.KinectSensors.FirstOrDefault(sensor => sensor.Status == KinectStatus.Connected);
// 此处调用kinect的set方法，注意 this.Kinect 而不是 this.kinect
} private void KinectSensors_StatusChanged(object sender, StatusChangedEventArgs e)
{
switch (e.Status)
{
case KinectStatus.Connected:
if (this.kinect == null)
this.kinect = e.Sensor;
break;
case KinectStatus.Disconnected:
if (this.kinect == e.Sensor)
{
this.kinect = null;
this.kinect = KinectSensor.KinectSensors.FirstOrDefault(x => x.Status == KinectStatus.Connected);
if (this.kinect == null)
{
//TODO:通知用于Kinect已拔出
}
}
break;
//TODO:处理其他情况下的状态
}
} private void kinectSensor_DepthFrameReady(Object sender,DepthImageFrameReadyEventArgs e)
{
if (lastDepthFrame!=null)
{
lastDepthFrame.Dispose();
lastDepthFrame = null;
}
lastDepthFrame = e.OpenDepthImageFrame();
if (lastDepthFrame!=null)
{
depthPixelDate = new short[lastDepthFrame.PixelDataLength];
lastDepthFrame.CopyPixelDataTo(depthPixelDate);
depthImageBitMap.WritePixels(depthImageBitmapRect, depthPixelDate, depthImageStride, ); CreateColorDepthImage(this.lastDepthFrame, depthPixelDate);
}
} private void CreateColorDepthImage(DepthImageFrame depthFrame, short[] pixelData)
{
Int32 depth;
Double hue;
Int32 loThreshold = ;
Int32 hiThreshold = ;
Int32 bytesPerPixel = ;
byte[] rgb=new byte[]; byte[] enhPixelData=new byte[depthFrame.Width*depthFrame.Height*bytesPerPixel]; for (int i = , j = ; i < pixelData.Length;i++,j+=bytesPerPixel )
{
depth = pixelData[i] >> DepthImageFrame.PlayerIndexBitmaskWidth;
if (depth<loThreshold || depth>hiThreshold)
{
enhPixelData[j] = 0x00;
enhPixelData[j + ] = 0x00;
enhPixelData[j + ] = 0x00;
}
else
{
hue = (( * depth / 0xFFF) + loThreshold);
ConvertHslToRgb(hue, , , rgb); enhPixelData[j] = rgb[]; //blue
enhPixelData[j + ] = rgb[]; // green;
enhPixelData[j + ] = rgb[]; //red }
} EnhancedDepthImage.Source = BitmapSource.Create(depthFrame.Width, depthFrame.Height, , , PixelFormats.Bgr32, null, enhPixelData, depthFrame.Width * bytesPerPixel);
} private void ConvertHslToRgb(double hue,double saturation,double lightness,byte[] rgb)
{
double red = 0.0;
double green = 0.0;
double blue = 0.0; hue = hue % ;
saturation = saturation / 100.0;
lightness = lightness / 100.0; if (saturation==0.0)
{
red = lightness;
green = lightness;
blue = lightness;
}
else
{
double huePrime = hue / 60.0;
int x = (int)huePrime;
double xPrime = huePrime - (double)x; ;
double L0 = lightness * (1.0 - saturation);
double L1 = lightness * (1.0 - (saturation * xPrime));
double L2 = lightness * (1.0 - (saturation * (1.0 - xPrime))); switch (x)
{
case :
red = lightness;
green = L2;
blue = L0;
break;
case :
red = L1;
green = lightness;
blue = L0;
break;
case :
red = L0;
green = lightness;
blue = L2;
break;
case :
red = L0;
green = L1;
blue = lightness;
break;
case :
red = L2;
green = L0;
blue = lightness;
break;
case :
red = lightness;
green = L0;
blue = L1;
break;
}
} rgb[] = (byte)(255.0 * red);
rgb[] = (byte)(255.0 * green);
rgb[] = (byte)(255.0 * blue);
} private void DepthImage_MouseLeftButtonUp(Object sender, MouseButtonEventArgs e)
{
Point p = e.GetPosition(DepthImage);
if (depthPixelDate!=null&&depthPixelDate.Length>)
{
Int32 pixelIndex = (Int32)(p.X + ((Int32)p.Y * this.lastDepthFrame.Width));
Int32 depth = this.depthPixelDate[pixelIndex] >> DepthImageFrame.PlayerIndexBitmaskWidth;
Int32 depthInches = (Int32)(depth * 0.0393700787);
Int32 depthFt = depthInches / ;
depthInches = depthInches % ; PixelDepth.Text = string.Format("{0}mm~{1}'{1}", depth, depthFt, depthInches);
}
} private void CreateLighterShadesOfGray(DepthImageFrame depthFrame, short[] pixelData)
{
Int32 depth;
Int32 loThreshold = ;
Int32 hiThreshold = ;
short[] enhPixelData= new short[depthFrame.Width*depthFrame.Height]; for (int i = ; i < pixelData.Length;i++ )
{
depth = pixelData[i] >> DepthImageFrame.PlayerIndexBitmaskWidth;
if (depth<loThreshold || depth>hiThreshold)
{
enhPixelData[i] = 0xFF;
}
else
{
enhPixelData[i]=(short)~pixelData[i];
}
} EnhancedDepthImage.Source = BitmapSource.Create(depthFrame.Width, depthFrame.Height, , , PixelFormats.Gray16, null, enhPixelData, depthFrame.Width * depthFrame.BytesPerPixel);
} private void CreateBetterShadesOfGray(DepthImageFrame depthFrame, short[] pixelData)
{
Int32 depth;
Int32 gray;
Int32 loThreashold = ;
Int32 bytePerPixel = ; // 4个通道只用前面3个bgr
Int32 hiThreshold = ;
byte[] enhPixelData = new byte[depthFrame.Width * depthFrame.Height * bytePerPixel];
for (int i = , j = ; i < pixelData.Length; i++, j += bytePerPixel)
{
depth = pixelData[i] >> DepthImageFrame.PlayerIndexBitmaskWidth;
if (depth < loThreashold || depth > hiThreshold)
{
gray = 0xFF;
}
else
{
gray = ( * depth / 0xFFF);
}
enhPixelData[j] = (byte)gray;
enhPixelData[j + ] = (byte)gray;
enhPixelData[j + ] = (byte)gray; }
EnhancedDepthImage.Source = BitmapSource.Create(depthFrame.Width, depthFrame.Height, , , PixelFormats.Bgr32, null, enhPixelData, depthFrame.Width * bytePerPixel);
} }
}
C#的set方法 ~~ 这个错误找了半天 ~~