Latest Contributions by EricWeber

I want to clip a raster and retain the NoData value from the source raster in the clipped raster. In the method below, I follow these steps: (1) use map algebra to clip the source raster to the new extent (2) use IRasterProps to set the pixel type and NoData value to be the same as the source raster (3) use ISaveAs to save the new raster dataset The source raster I've been testing with is a 16-bit signed integer raster with a NoData value of -32768. Setting the pixel type works correctly, but the NoData value always ends up being 32767. I have also tried using the geoprocessing clip method (http://help.arcgis.com/en/sdk/10.0/arcobjects_net/conceptualhelp/index.html#/How_to_clip_a_raster_dataset_with_an_envelope_or_a_dataset/0001000000n5000000/), but I still end up with 32767. (Other specifics in my testing that may or may not be relevant: input raster is GRID, output is file geodatabase)         public static IRaster ClipRaster(IRaster2 sourceRaster, IEnvelope extent, IWorkspace workspace, string rasterName, string rasterFormat)         {             //map algebra method for clipping             //NoData value is not set properly (always ends up as largest positive integer supported by pixel type)             //clip             SetRasterAnalysisEnvCellSize(sourceRaster, true);             SetRasterAnalysisEnvExtent(extent, sourceRaster, true);             IMapAlgebraOp mapAlgebraOp = new RasterMapAlgebraOpClass();             string rasterSymbol = "source";             mapAlgebraOp.BindRaster((IGeoDataset)sourceRaster, rasterSymbol);             IGeoDataset tempClipRaster = mapAlgebraOp.Execute("[" + rasterSymbol + "]");                      //set pixel type and nodata value to match input raster and save             IRasterProps propsClip = tempClipRaster as IRasterProps;             IRasterProps propsSource = sourceRaster as IRasterProps;             propsClip.PixelType = propsSource.PixelType;             propsClip.NoDataValue = propsSource.NoDataValue; // this doesn't stick             IRasterDataset3 clipOutput = ((ISaveAs2)tempClipRaster).SaveAs(rasterName, workspace, rasterFormat) as IRasterDataset3;                         //delete the temporary dataset created by the map algebra op             if (((IDataset)((IRaster2)tempClipRaster).RasterDataset).CanDelete())                 ((IDataset)((IRaster2)tempClipRaster).RasterDataset).Delete();             IRaster outRaster = clipOutput.CreateDefaultRaster();             //IRaster outRaster = clipOutput.CreateFullRaster(); //this method has same result             return outRaster;         } ... View more

I have the following method for writing pixel edits to a raster:         private void RectangularRasterEdit(IRaster raster, IPnt topLeft, int widthInCells, int heightInCells, List<int> newPixelValues)         {             //rasterband             //IRasterBand rasterBand = ((IRasterBandCollection)raster).Item(0);             //pixel block size             IPnt blockSize = new PntClass();             blockSize.X = widthInCells;             blockSize.Y = heightInCells;             //create pixel block             //IPixelBlock pixelBlock = ((IRawPixels)rasterBand).CreatePixelBlock(blockSize);             IPixelBlock pixelBlock = raster.CreatePixelBlock(blockSize);             //build array of new values to be written to raster             short[,] pixels = new short[widthInCells, heightInCells];             int newValueIndex = 0;             for (int i = 0; i < widthInCells; i++)             {                 for (int j = 0; j < heightInCells; j++)                 {                     pixels[i, j] = (short)newPixelValues[newValueIndex];                     newValueIndex++;                 }             }             //update pixel block with new pixel array             ((IPixelBlock3)pixelBlock).set_PixelData(0, pixels);                         //write changed pixelblock to raster             //((IRawPixels)rasterBand).Write(topLeft, pixelBlock);             ((IRasterEdit)raster).Write(topLeft, pixelBlock);             ((IRasterEdit)raster).Refresh();         } This method can handle rectangles of any size, but I use it mostly for one-cell edits (pixelBlock is 1 X 1). The problem is that when I try to edit a cell in the rightmost column or in the bottom row of the raster, the IRasterEdit.Write method fails (with a generic HRESULT). I have tried the IRawPixels.Write method as well (the code for that is in comments above), but get the same error. For example, say I have a raster that is 6 pixels by 6 pixels. If I pass a 1X1 pixelBlock to the write method, and the top left corner contains a 5 for either the row or column, it fails. Also, after some testing, I verified that there is no problem reading a 1X1 pixel block using the same top left corner. The problem only occurs when trying to write. Any ideas what might be causing this issue? ... View more