IPixelBlock chongxin zhengli

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

using ESRI.ArcGIS.DataSourcesRaster;
using ESRI.ArcGIS.DataSourcesFile;
using ESRI.ArcGIS.Geodatabase;
using ESRI.ArcGIS.esriSystem;
using ESRI.ArcGIS.Geometry;

namespace _4个像素合并成1个像素
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private  IRasterDataset pPublicRasterdataset;
        private IRasterWorkspace2 pPublicRasterWorkspace2;
        private IRasterWorkspace pPublicRasterWorkspace;

       
        private void Pathbutton_Click(object sender, EventArgs e)
        {
            try
            {
                OpenFileDialog opd = new OpenFileDialog();
              
                //opd.InitialDirectory = @"C:\";
                opd.Filter = "IMAGINE(*.img)|*.img";
                opd.FilterIndex = 1;
                opd.RestoreDirectory = true;
                string filepath, filename;

                if (opd.ShowDialog() == DialogResult.OK && opd.FileName.Length > 0)
                {
                    PathtextBox.Text = opd.FileName;
                    int index = opd.FileName.LastIndexOf("\\");
                    filepath = opd.FileName.Substring(0, index + 1);
                    filename = opd.FileName.Substring(index + 1);

                    IWorkspaceFactory workspaceFactory = new RasterWorkspaceFactory();
                    IWorkspace workspace;
                    workspace = workspaceFactory.OpenFromFile(filepath, 0); //inPath栅格数据存储路径

                    IRasterWorkspace rastWork = (IRasterWorkspace)workspace;
                    IRasterDataset rastDataset;
                    rastDataset = rastWork.OpenRasterDataset(filename) as IRasterDataset;//inName栅格文件名

                    pPublicRasterdataset = rastDataset;
                    pPublicRasterWorkspace2 = (IRasterWorkspace2)rastWork;
                    pPublicRasterWorkspace = rastWork;

                }
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.ToString());
            }
        }
        private float GetMax(List<float> list)
        {
            float max = list[0];
            foreach (float d in list)
            {
                if (d >= max)
                    max = d;
            }
            return max;
 
        }
        private float GetMin(List<float> list)
        {
            float min = list[0];
            foreach (float d in list)
            {
                if (d <= min)
                    min = d;
            }
            return min;

        }

        //public IRasterWorkspace2 createRasterWorkspace(string pathName)
        //{
        //    // Create RasterWorkspace
        //    IWorkspaceFactory workspaceFactory = new RasterWorkspaceFactoryClass();
        //    return workspaceFactory.OpenFromFile(pathName, 0) as IRasterWorkspace2;
        //}

        //float = ushort
        private int windowWidth = 0;
        private void Generatebutton_Click(object sender, EventArgs e)
        {
            try
            {

                windowWidth = int.Parse(MergetextBox.Text);

                List<float> pixelblocklist;

                IRaster pRaster = pPublicRasterdataset.CreateDefaultRaster();

                IRasterProps rasterProps = (IRasterProps)pRaster;
               
                int dHeight = rasterProps.Height;//当前栅格数据集的行数
                int dWidth = rasterProps.Width; //当前栅格数据集的列数
                double dX = rasterProps.MeanCellSize().X; //栅格的宽度
                double dY = rasterProps.MeanCellSize().Y; //栅格的高度
                IEnvelope extent = rasterProps.Extent; //当前栅格数据集的范围
                rstPixelType pixelType = rasterProps.PixelType; //当前栅格像素类型8bit、16bit等等
                ISpatialReference spatialRefenence = rasterProps.SpatialReference;//

                //set value to rasterdataset
                IPnt pntSize = new DblPntClass();
                pntSize.SetCoords(windowWidth * dX, windowWidth * dY); //创建像块大小为2dX*2dY，用坐标来表示的pixel

                IPixelBlock pixelBlock = pRaster.CreatePixelBlock(pntSize);
                IPnt pnt = new PntClass();
                float[,] Mergevalues = new float[dWidth / windowWidth, dHeight / windowWidth];
                float count = 0;
                MainprogressBar.Minimum = 0;
                MainprogressBar.Maximum = ((dWidth / windowWidth) - 1)/5;
                MainprogressBar.Step = 1;

                for (int i = 0; i < (dWidth - dWidth % windowWidth); )
                {
                    for (int j = 0; j < (dHeight - dHeight % windowWidth); )
                    {

                        pnt.SetCoords(i, j);
                        pRaster.Read(pnt, pixelBlock);

                        if (pixelBlock != null)
                        {
                            pixelblocklist = new List<float>();

                            for (int k = 0; k < windowWidth; k++)
                            {
                                for (int w = 0; w < windowWidth; w++)
                                {
                                   
                                    pixelblocklist.Add(Convert.ToSingle(pixelBlock.GetVal(0, k, w)));

                                }
                            }

   
                            Mergevalues[i / windowWidth, j / windowWidth] = (float)(GetMax(pixelblocklist) - GetMin(pixelblocklist));
                            pixelblocklist = null;

                        }

                        j += windowWidth;
                    }

                    //MainprogressBar.Update();
                    //MainprogressBar.Value = (int)count++;
                    //MainprogressBar.Update();
                    if (MainprogressBar.Value + 5 < MainprogressBar.Maximum)
                    {
                        MainprogressBar.Increment(5);
                    }

                   
                    i += windowWidth;
                }

                //generate new rasterdataset
                IRasterDataset rasterDataset;
                IPoint originPoint = new ESRI.ArcGIS.Geometry.Point();
                //这里也要注意，原点为extent.XMin, extent.YMin + (dHeight % windowWidth) * dY
                originPoint.PutCoords(extent.XMin, extent.YMin + (dHeight % windowWidth) * dY);

                //只是create，并没有open
                rasterDataset = pPublicRasterWorkspace2.CreateRasterDataset(NewNametextBox.Text + ".img", "IMAGINE Image", originPoint,
                    dWidth / windowWidth, dHeight / windowWidth, dX * windowWidth, dY * windowWidth, 1, pixelType, spatialRefenence, true);

                //rasterDataset = pPublicRasterWorkspace.OpenRasterDataset("new.img");

                IRawPixels rawPixels = null;
                IPixelBlock3 pixelBlock3 = null;
                IPnt pixelBlockOrigin = null;
                IPnt pixelBlockSize = null;
                IRasterBandCollection rasterBandCollection;
                IRasterProps rasterPropsAgain;

                // QI for IRawPixels and IRasterProps
                rasterBandCollection = (IRasterBandCollection)rasterDataset;
                rawPixels = (IRawPixels)rasterBandCollection.Item(0);
                rasterPropsAgain = (IRasterProps)rawPixels;

                // Create pixelblock
                pixelBlockOrigin = new DblPntClass();
               
                //在这里我犯了致命错误，pixelblock原点从左上角开始计算，与创建rasterdataset不同（原点是右下角） zhangjun here
                //pixelBlockOrigin.SetCoords(extent.XMin, extent.YMin + (dHeight % windowWidth) * dY);
                pixelBlockOrigin.SetCoords(0, 0);

                pixelBlockSize = new DblPntClass();
                //pixelBlockSize.SetCoords(0, 0); //NOYIICE Width is X and Height is Y ERROR!
                pixelBlockSize.SetCoords(rasterPropsAgain.Width, rasterPropsAgain.Height);

                pixelBlock3 = (IPixelBlock3)rawPixels.CreatePixelBlock(pixelBlockSize);

                // Read pixelblock
                rawPixels.Read(pixelBlockOrigin, (IPixelBlock)pixelBlock3);

                // Get pixeldata array
                System.Array pixelData;
                pixelData = (System.Array)pixelBlock3.get_PixelDataByRef(0);

                // Loop through all the pixels and assign value;    Width is X ;Height is Y; width*height = X*Y
                for (int i = 0; i < rasterPropsAgain.Width; i++)
                    for (int j = 0; j < rasterPropsAgain.Height; j++)
                        pixelData.SetValue(Convert.ToUInt16(Mergevalues[i, j]), i, j);

                pixelBlock3.set_PixelData(0, (System.Object)pixelData);

                // Write the pixeldata back
                System.Object cachePointer;

                cachePointer = rawPixels.AcquireCache();

                rawPixels.Write(pixelBlockOrigin, (IPixelBlock)pixelBlock3);

                rawPixels.ReturnCache(cachePointer);

                MessageBox.Show("生成像块完毕！");

            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.ToString());
            }

       }

    
    }
}