mikedavies

Statistics not calculate when creating a TIFF/Imagine raster in ArcGIS 10

Discussion created by mikedavies on Feb 16, 2011
Hi,

I'm having problems getting some code working in ArcGis 10, that had previous worked in 9.3.

I am generating a raster and then tryng to save it.  If I save it as a GRID, everything is ok.  But if I save it as TIFF or Imagine, no raster statistics get generated.  For example, ArcMap / Layer Properties / Source says 'Statistics have not been calculated' and the symbology shows the range of  values as 0-255 for a 8-bit raster.  The raster (pixel) data appears to be saved correctly - it's simply missing the statistics.

I have simplified our code to produce a demonstration - see code below - almost identical for the working/failing cases.  This is invoked in a BaseCommand in ArcMap.

Mike.

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        private void test1b()
        {
            string foldername = @"C:\xxxxx\rasters";
#if false
            // this works ok, with statistics in the Grid
            string filename_temp = "testras_temp";
            string filename_perm = "testras_perm";
            string saveas = "GRID";
#else
            // this produces a TIFF but with 'Statistics have not not calculated'
            string filename_temp = "testras_temp.tif";
            string filename_perm = "testras_perm.tif";
            string saveas = "TIFF";
#endif
            // geometry of new raster
            Point por = new Point();
            por.PutCoords(0, 0);
            IPnt psize = new PntClass();
            psize.SetCoords(100, 100);

            // raster workspace ..
            RasterWorkspaceFactory rwf = new RasterWorkspaceFactory();
            IRasterWorkspace2 rws = rwf.OpenFromFile(foldername, 0) as IRasterWorkspace2;

            // spatial ref ...
            ISpatialReferenceFactory2 srefFact = new SpatialReferenceEnvironmentClass();
            ISpatialReference sref = srefFact.CreateProjectedCoordinateSystem((int)esriSRProjCSType.esriSRProjCS_BritishNationalGrid);

            // create a raster dataset
            IRasterDataset rds = rws.CreateRasterDataset(filename_temp, saveas,
                por, (int)psize.X, (int)psize.Y, 1, 1,
                1, rstPixelType.PT_UCHAR, sref, false);

            // and the raster to be returned
            IRaster ras = rds.CreateDefaultRaster();

            // prepare for some pixels
            IRawPixels rawpix = (rds as IRasterBandCollection).Item(0) as IRawPixels;
            IPixelBlock3 pb = rawpix.CreatePixelBlock(psize) as IPixelBlock3;

            IRasterProps rprop = (rds as IRasterBandCollection).Item(0) as IRasterProps;
            rprop.NoDataValue = (byte)255;

            System.Array pixelarray = pb.get_PixelDataByRef(0) as System.Array;
            for (int col = (int)por.X; col < psize.X; col++)
            {
                for (int row = (int)por.Y; row < psize.Y; row++)
                {
                    byte val = (col != row) ? (byte) rprop.NoDataValue : (byte) row;
                    pixelarray.SetValue(val, col, row);
                }
            }
            pb.set_PixelData(0, (System.Object)pixelarray);

            // write the raster to temp
            IPnt porw = new PntClass();
            porw.SetCoords(por.X, por.Y);
            (ras as IRasterEdit).Write(porw, (IPixelBlock)pb);

            // this just flushes the temporary raster
            //(ras as IRasterEdit).Refresh();

            // save a permanent raster
            (ras as ISaveAs).SaveAs(filename_perm, rws as IWorkspace, saveas);
        }

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