private short[] extractDepthImage(NuiImageBuffer buf)
 {
     DepthBuffer db = (DepthBuffer)Marshal.PtrToStructure(buf.m_pBuffer,typeof(DepthBuffer));
     return db.pixels;
 }
 private Color32[] extractColorImage(NuiImageBuffer buf)
 {
     int totalPixels = buf.m_Width * buf.m_Height;
     Color32[] colorBuf = colorImage;
     ColorBuffer cb = (ColorBuffer)Marshal.PtrToStructure(buf.m_pBuffer,typeof(ColorBuffer));
     for (int pix = 0; pix < totalPixels; pix++)
     {
         colorBuf[pix].r = cb.pixels[pix].r;
         colorBuf[pix].g = cb.pixels[pix].g;
         colorBuf[pix].b = cb.pixels[pix].b;
     }
     return colorBuf;
 }