Beispiel #1
0
        /// <summary>
        /// 通过Feature设置栅格无效值
        /// </summary>
        /// <param name="polyFeat"></param>
        /// <param name="inDs"></param>
        public static void setNoData(Feature polyFeat, Dataset inDs)
        {
            //注册库
            Gdal.AllRegister();
            Ogr.RegisterAll();

            //Get Geometry & Envelope
            Geometry Geom = polyFeat.GetGeometryRef();
            Envelope enve = new Envelope();

            Geom.GetEnvelope(enve);

            //Get all Transform
            double[] GeoTransform = new double[6];
            inDs.GetGeoTransform(GeoTransform);

            // Envelope Conver to ImgSpace -- off to end
            int xoff, yoff, xend, yend;

            StaticTools.geoToImageSpace(GeoTransform, enve.MinX, enve.MaxY, out xoff, out yoff);
            StaticTools.geoToImageSpace(GeoTransform, enve.MaxX, enve.MinY, out xend, out yend);
            int xsize = xend - xoff;
            int ysize = yend - yoff;

            //Get The Values
            double[] rasterValues = new double[xsize * ysize];
            inDs.GetRasterBand(1).ReadRaster(xoff, yoff, xsize, ysize, rasterValues, xsize, ysize, 0, 0);

            //Get new Transform
            double[] NewTransform = GeoTransform;
            NewTransform[0] = enve.MinX;
            NewTransform[3] = enve.MaxY;

            //无效值,特定值
            double noData = 9999;

            for (int iline = 0; iline < ysize; iline++)
            {
                for (int iPixel = 0; iPixel < xsize; iPixel++)
                {
                    Geometry poiGeom = new Geometry(wkbGeometryType.wkbPoint);
                    double   x, y;
                    StaticTools.imageToGeoSpace(NewTransform, iPixel, iline, out x, out y);
                    poiGeom.AddPoint_2D(x, y);
                    if (poiGeom.Within(Geom))
                    {
                        rasterValues[iline * xsize + iPixel] = noData;
                    }
                    poiGeom.Dispose();
                }
            }
            inDs.GetRasterBand(1).WriteRaster(xoff, yoff, xsize, ysize, rasterValues, xsize, ysize, 0, 0);
            inDs.Dispose();
            polyFeat.Dispose();
        }