/// <summary>
/// 栅格重建，srPath输入，dsPath输出，1为1=>1, 2为1=>4, 3为1=>9,
/// </summary>
/// <param name="srPath"></param>
/// <param name="dsPath"></param>
/// <param name="level"></param>
public static void ImgReProject(string srPath, string dsPath, int level = 2)
{
Console.WriteLine("ReprojectImage开始，lever 2");
double[] geoTran = new double[6];
double[] geoTran2 = new double[6];
//读
OSGeo.GDAL.Gdal.AllRegister();
Dataset ds = Gdal.Open(srPath, Access.GA_ReadOnly);
ds.GetGeoTransform(geoTran);
geoTran2 = geoTran;
geoTran2[1] = geoTran[1] / level;
geoTran2[5] = geoTran[5] / level;
//建
OSGeo.GDAL.Driver gdalDriver = Gdal.GetDriverByName("HFA");
Dataset ods = gdalDriver.Create(dsPath, ds.RasterXSize * level, ds.RasterYSize * level, 1, DataType.GDT_Float32, null);
ods.SetProjection(ds.GetProjection());
ods.SetGeoTransform(geoTran2);
ods.GetRasterBand(1).SetNoDataValue(-999999);
//写
Gdal.ReprojectImage(ds, ods, null, null, ResampleAlg.GRA_NearestNeighbour, 0, 0.02, null, null);
ds.Dispose();
ods.Dispose();
Console.WriteLine("ReprojectImage完成");
}
private static void StartClippingProcess(Layer layer, string rasterName, double rasterCellSize, out Dataset outAlignedRaster)
{
DriverUtils.RegisterGdalOgrDrivers();
//Extrac srs from input feature
string inputShapeSrs;
SpatialReference spatialRefrence = layer.GetSpatialRef();
spatialRefrence.ExportToWkt(out inputShapeSrs);
Envelope envelope = new Envelope();
layer.GetExtent(envelope, 0);
//Compute the out raster cell resolutions
int x_res = Convert.ToInt32((envelope.MaxX - envelope.MinX) / rasterCellSize);
int y_res = Convert.ToInt32((envelope.MaxY - envelope.MinY) / rasterCellSize);
Dataset oldRasterDataset = Gdal.Open(rasterName, Access.GA_ReadOnly);
//No of bands in older dataset
int rasterBands = oldRasterDataset.RasterCount;
//Create new tiff in disk
string tempRaster = "tempValueRaster.tif";
if (File.Exists(tempRaster))
{
File.Delete(tempRaster);
}
OSGeo.GDAL.Driver outputDriver = Gdal.GetDriverByName("GTiff");
outAlignedRaster = outputDriver.Create(tempRaster, x_res, y_res, rasterBands, DataType.GDT_Float32, null);
//Geotransform
double[] argin = new double[] { envelope.MinX, rasterCellSize, 0, envelope.MaxY, 0, -rasterCellSize };
outAlignedRaster.SetGeoTransform(argin);
//Set no data
for (int rasBand = 1; rasBand <= rasterBands; rasBand++)
{
Band band = outAlignedRaster.GetRasterBand(rasBand);
band.Fill(GdalUtilConstants.NoDataValue, 0.0);
}
//band.SetNoDataValue(GdalUtilConstants.NoDataValue);
outAlignedRaster.SetProjection(inputShapeSrs);
string[] reprojectOptions = { "NUM_THREADS = ALL_CPUS", "WRITE_FLUSH = YES" };
Gdal.ReprojectImage(oldRasterDataset, outAlignedRaster, null, inputShapeSrs, ResampleAlg.GRA_NearestNeighbour, 0.0, 0.0, null, null, reprojectOptions);
//flush cache
oldRasterDataset.FlushCache();
oldRasterDataset.Dispose();
}
/// <summary>
/// Scales down query dataset to the tile dataset.
/// </summary>
/// <param name="queryDataset">Source dataset.</param>
/// <param name="tileDataset">Destination dataset.</param>
/// <param name="resampling">Resampling method.</param>
private static void ScaleQueryToTile(Dataset queryDataset, Dataset tileDataset, ResampleAlg resampling)
{
queryDataset.SetGeoTransform(new[]
{
0.0,
Convert.ToSingle(tileDataset.RasterXSize) / queryDataset.RasterXSize,
0.0, 0.0, 0.0,
Convert.ToSingle(tileDataset.RasterXSize) / queryDataset.RasterXSize
});
tileDataset.SetGeoTransform(new[] { 0.0, 1.0, 0.0, 0.0, 0.0, 1.0 });
Gdal.ReprojectImage(queryDataset, tileDataset, null, null, resampling, 0.0, 0.0, null, null, null);
}
// 将给定Tif转换为Web Mercator投影
public void TransformTiff(Dataset ds, double[] VerticeX, double[] VerticeY, string FilePath, ResampleAlg eResampleMethod)
{
//获取Web墨卡托坐标系
SpatialReference Mercator = new SpatialReference("");
Mercator.ImportFromEPSG(3857); // Web Mercator
Mercator.SetMercator(0d, 0d, 1d, 0d, 0d);
string MercatorWkt;
Mercator.ExportToWkt(out MercatorWkt);
//原栅格坐标信息
SpatialReference Raster_spf = new SpatialReference(ds.GetProjectionRef());
//影像四个顶点投影转换
CoordinateTransformation coordinateTrans = Osr.CreateCoordinateTransformation(Raster_spf, Mercator);
coordinateTrans.TransformPoints(4, VerticeX, VerticeY, null); //VerticeX和VerticeY存储的是影像四个顶点坐标
coordinateTrans.Dispose();
//计算重投影后栅格顶点坐标
double dbMinx = 0;
double dbMaxx = 0;
double dbMiny = 0;
double dbMaxy = 0;
dbMinx = Math.Min(Math.Min(Math.Min(VerticeX[0], VerticeX[1]), VerticeX[2]), VerticeX[3]);
dbMaxx = Math.Max(Math.Max(Math.Max(VerticeX[0], VerticeX[1]), VerticeX[2]), VerticeX[3]);
dbMiny = Math.Min(Math.Min(Math.Min(VerticeY[0], VerticeY[1]), VerticeY[2]), VerticeY[3]);
dbMaxy = Math.Max(Math.Max(Math.Max(VerticeY[0], VerticeY[1]), VerticeY[2]), VerticeY[3]);
//计算新的仿射变换参数
double[] newTransform = new double[6];
newTransform[0] = dbMinx; //左上角点x坐标
newTransform[3] = dbMaxy; //左上角点y坐标
newTransform[1] = 100; //像素宽度
newTransform[5] = -100; //像素高度
//计算大小
int width = (int)Math.Ceiling(Math.Abs(dbMaxx - dbMinx) / 100.0);
int height = (int)Math.Ceiling(Math.Abs(dbMaxy - dbMiny) / 100.0);
//创建新的栅格影像
OSGeo.GDAL.Driver pGDalDriver = Gdal.GetDriverByName("GTiff");
Dataset poDataset = pGDalDriver.Create(FilePath, width, height, 1, DataType.GDT_Float32, null);
poDataset.SetGeoTransform(newTransform);
poDataset.SetProjection(MercatorWkt);
//重投影
Gdal.ReprojectImage(ds, poDataset, ds.GetProjectionRef(), MercatorWkt, eResampleMethod, 0, 0, new Gdal.GDALProgressFuncDelegate(ProgressFunc), null, null);
//设置NoData值
Band band = poDataset.GetRasterBand(1);
band.SetNoDataValue(-10000000);
poDataset.FlushCache();
poDataset.Dispose();
}