C#+ArcEngine：点云的投影点密度（DoPP）特征图像（ArGIS10.1、VS2010窗体+代码 ）

   

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/// <summary>
/// 1、定义结构体
/// </summary>
struct LasGridInfo
{
    public double MinX;
    public double MinY;
    public double GSD;
    public int SumRow;
    public int SumCol;
    public int SumGN;
}

/// <summary>
/// 2、划分格网，确定DoPP
/// </summary>
/// <param name="LasFileFullName"></param>
/// <param name="xjLasGridInfo"></param>
/// <returns></returns>
private Hashtable xjDividePointToGrid(string LasFileFullName, ref LasGridInfo xjLasGridInfo)
{
    Hashtable xjHtAllGridPoint = new Hashtable();

    #region Las文件的基本信息
    LASReader xjLASReader = new LASReader(LasFileFullName);
    LASHeader xjLASHeader = xjLASReader.GetHeader();
    double xjMaxX = xjLASHeader.GetMaxX();
    double xjMinX = xjLASHeader.GetMinX();
    double xjMaxY = xjLASHeader.GetMaxY();
    double xjMinY = xjLASHeader.GetMinY();
    xjLasGridInfo.MinX = xjMinX;
    xjLasGridInfo.MinY = xjMinY;

    double ThrGSD = xjLasGridInfo.GSD;
    int xjSumRow = (int)((xjMaxY - xjMinY) / ThrGSD) + 1;//总行数
    int xjSumCol = (int)((xjMaxX - xjMinX) / ThrGSD) + 1;//总列数
    int xjGridCount = xjSumRow * xjSumCol;
    xjLasGridInfo.SumRow = xjSumRow;
    xjLasGridInfo.SumCol = xjSumCol;
    xjLasGridInfo.SumGN = xjGridCount;
    #endregion

    int xjRowNumber = 0;
    int xjColNumber = 0;
    int xjGridNumber = 0;
    while (xjLASReader.GetNextPoint())
    {
        LASPoint xjLASPoint = xjLASReader.GetPoint();
        xjRowNumber = (int)((xjLASPoint.Y - xjMinY) / ThrGSD) + 1;
        xjColNumber = (int)((xjLASPoint.X - xjMinX) / ThrGSD) + 1;
        xjGridNumber = (xjRowNumber - 1) * xjSumCol + xjColNumber;

        if (!xjHtAllGridPoint.ContainsKey(xjGridNumber))
        {
            xjHtAllGridPoint.Add(xjGridNumber, 1);
        }
        else
        {
            int xjCount = (int)xjHtAllGridPoint[xjGridNumber];
            xjHtAllGridPoint.Remove(xjGridNumber);
            xjHtAllGridPoint.Add(xjGridNumber, xjCount + 1);
        }
    }

    return xjHtAllGridPoint;
}

/// <summary>
/// 3、输出特征图像
/// </summary>
/// <param name="HtDoPP"></param>
/// <param name="xjLasGridInfo"></param>
/// <param name="ExportLasFullName"></param>
private void xjOutputTiff(Hashtable HtDoPP, LasGridInfo xjLasGridInfo, string ExportLasFullName)
{
    string xjOutRasterPath = System.IO.Path.GetDirectoryName(ExportLasFullName);
    IRasterDataset xjOutRasterDataset = CreateRasterDataset(xjOutRasterPath, ExportLasFullName, xjLasGridInfo.MinX, 
        xjLasGridInfo.MinY, xjLasGridInfo.GSD, HtDoPP, xjLasGridInfo.SumRow, xjLasGridInfo.SumCol);
    IRasterLayer xjOutRasterLayer = new RasterLayerClass();
    xjOutRasterLayer.CreateFromDataset(xjOutRasterDataset);
    ILayer xjOutLayer = xjOutRasterLayer;
    xjOutRasterLayer.Name = ExportLasFullName;
}

/// <summary>
/// 3.1 创建栅格数据集
/// </summary>
/// <param name="FileDirectoryName"></param>
/// <param name="FielName"></param>
/// <param name="G_Xmin"></param>
/// <param name="G_Ymin"></param>
/// <param name="G_GridSide"></param>
/// <param name="G_Hashtable"></param>
/// <param name="G_RowSum"></param>
/// <param name="G_ColumnSum"></param>
/// <returns></returns>
private IRasterDataset CreateRasterDataset(string FileDirectoryName, string FielName, double G_Xmin, 
        double G_Ymin, double G_GridSide, Hashtable G_Hashtable, int G_RowSum, int G_ColumnSum)
{
    //原点
    IPoint xjOriginPoint = new PointClass();
    xjOriginPoint.PutCoords(G_Xmin, G_Ymin);

    //创建数据集
    IWorkspaceFactory xjWorkspaceFactory = new RasterWorkspaceFactoryClass();
    IRasterWorkspace2 xjRasterWorkspace = xjWorkspaceFactory.OpenFromFile(FileDirectoryName, 0) as IRasterWorkspace2;
    IRasterDataset xjRasterDataset = xjRasterWorkspace.CreateRasterDataset(FielName, "TIFF", xjOriginPoint, G_ColumnSum,
      G_RowSum, G_GridSide, G_GridSide, 1, rstPixelType.PT_DOUBLE, new UnknownCoordinateSystemClass(), true);

    IRasterBandCollection xjRasterBandCollection = (IRasterBandCollection)xjRasterDataset;
    IRasterBand xjRasterBand = xjRasterBandCollection.Item(0);
    IRasterProps xjRasterProps = (IRasterProps)xjRasterBand;
    xjRasterProps.NoDataValue = -1.0;

    IPnt xjPntPixelBlockOrigin = new DblPntClass();
    xjPntPixelBlockOrigin.SetCoords(0, 0);
    IPnt xjPntPixelBlockSize = new DblPntClass();
    xjPntPixelBlockSize.SetCoords(xjRasterProps.Width, xjRasterProps.Height);//（列数，行数）

    IRawPixels xjRawPixels = (IRawPixels)xjRasterBandCollection.Item(0);
    IPixelBlock3 xjPixelBlock3 = (IPixelBlock3)xjRawPixels.CreatePixelBlock(xjPntPixelBlockSize);
    xjRawPixels.Read(xjPntPixelBlockOrigin, (IPixelBlock)xjPixelBlock3);

    System.Array xjPixelData = (System.Array)xjPixelBlock3.get_PixelDataByRef(0);
    for (int i = 0; i < xjRasterProps.Width; i++)//列数
    {
        for (int j = 0; j < xjRasterProps.Height; j++)//行数
        {
            int GridIndex = (G_RowSum - j - 1) * G_ColumnSum + (i + 1);

            if (G_Hashtable.Contains(GridIndex))
            {
                double GridValueTemp = Convert.ToDouble(G_Hashtable[GridIndex]);
                xjPixelData.SetValue(GridValueTemp, i, j);
            }
            else
            {
                xjPixelData.SetValue(-1.0, i, j);
            }
        }
    }

    xjPixelBlock3.set_PixelData(0, (System.Object)xjPixelData);
    byte[] xjNoDataArray = (byte[])xjPixelBlock3.get_NoDataMaskByRef(0);
    xjPixelBlock3.set_NoDataMask(0, (System.Object)xjNoDataArray);

    System.Object xjCachePointer = xjRawPixels.AcquireCache();
    xjRawPixels.Write(xjPntPixelBlockOrigin, (IPixelBlock)xjPixelBlock3);
    xjRawPixels.ReturnCache(xjCachePointer);

    return xjRasterDataset;
}

VS2010窗体+代码：https://download.csdn.net/download/xinjiang666/11038353

参考文献：史文中,李必军,李清泉.基于投影点密度的车载激光扫描距离图像分割方法[J].测绘学报,2005(02):95-100.