GDAL重采样实现

using OSGeo.GDAL;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Resample1
{
    class Program
    {
        static void Main(string[] args)
        {
            string srcFileName = @"E:\GDAL\GDALPractice\GDAL_in_CSharp\chapter07\QQ20150414101043.tif";
            string dstFileName = @"E:\GDAL\GDALPractice\GDAL_in_CSharp\chapter07\result_resample1.tif";

            double xRatio = 0;
            double yRatio=0;
            bool b = false;
            while (b==false)
            {
                try
                {
                    //xRatio、yRatio大于1则图像变大，小于1则变小
                    Console.WriteLine("输入X方向的采样比例：");
                    xRatio = Convert.ToDouble(Console.ReadLine());
                    Console.WriteLine("输入Y方向的采样比例：");
                    yRatio = Convert.ToDouble(Console.ReadLine());
                    b = true;
                }
                catch
                {
                    Console.WriteLine("输入错误，请重新输入：");
                }
            }

            Gdal.AllRegister();
            Dataset srcDs = Gdal.Open(srcFileName, Access.GA_ReadOnly);
            Driver srcDrv=srcDs.GetDriver();
            Band srcBand = srcDs.GetRasterBand(1);
            DataType type = srcBand.DataType;

            int bandCount = srcDs.RasterCount;
            int iWidth = srcDs.RasterXSize;
            int iHeight = srcDs.RasterYSize;

            //根据采样比例计算重采样后的图像宽高
            int dstImgWidth = (int)(iWidth * xRatio + 0.5);
            int dstImgHeight = (int)(iHeight * yRatio + 0.5);

            double[] adfGeoTransform = new double[6];
            srcDs.GetGeoTransform(adfGeoTransform);

            //计算重采样后的图像分辨率
            adfGeoTransform[1] /= xRatio;
            adfGeoTransform[5] /= yRatio;
 
            //创建输出文件
            Driver dstDrv = Gdal.GetDriverByName("GTIFF");
            Dataset dstDs = dstDrv.Create(dstFileName, dstImgWidth, dstImgHeight, bandCount, DataType.GDT_Byte, null);
            dstDs.SetGeoTransform(adfGeoTransform);

            int[] bandNum = new int[bandCount];
            for(int i=0;i<bandCount;++i)
            {
                bandNum[i] = i + 1;
            }

            if(type==DataType.GDT_Byte)
            {
                byte[] dstArray = new byte[bandCount * dstImgHeight * dstImgWidth];
                srcDs.ReadRaster(0, 0, iWidth, iHeight, dstArray, dstImgWidth, dstImgHeight, bandCount, bandNum, 0, 0, 0);
                dstDs.WriteRaster(0, 0, dstImgWidth, dstImgHeight, dstArray, dstImgWidth, dstImgHeight, bandCount, bandNum, 0, 0, 0);
            }
            dstDs.FlushCache();
            dstDs.Dispose();
            Console.WriteLine("Success");
            Console.ReadLine();
        }
    }
}

原图：

效果：