/****************************************************************************** * $Id: GDALReadDirect.cs 13437 2007-12-21 21:02:38Z tamas $ * * Name: GDALDatasetRasterIO.cs * Project: GDAL CSharp Interface * Purpose: A sample app to read GDAL raster data directly to a C# bitmap. * Author: Tamas Szekeres, szekerest@gmail.com * ****************************************************************************** * Copyright (c) 2007, Tamas Szekeres * * Permission is hereby granted, free of charge, to any person obtaining a * copy of this software and associated documentation files (the "Software"), * to deal in the Software without restriction, including without limitation * the rights to use, copy, modify, merge, publish, distribute, sublicense, * and/or sell copies of the Software, and to permit persons to whom the * Software is furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included * in all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER * DEALINGS IN THE SOFTWARE. *****************************************************************************/ using System; using System.Drawing; using System.Drawing.Imaging; using System.Runtime.InteropServices; using OSGeo.GDAL; /** *

Title: GDAL C# GDALDatasetRasterIO example.

*

Description: A sample app to read GDAL raster data directly to a C# bitmap.

* @author Tamas Szekeres (szekerest@gmail.com) * @version 1.0 */ /// /// A C# based sample to read GDAL raster data directly to a C# bitmap. /// class GDALReadDirect { public static void usage() { Console.WriteLine("usage: GDALDatasetRasterIOEx {GDAL dataset name} {output file name} {scale = 0.5} {version = 1} {resample alg = GRIORA_NearestNeighbour}"); System.Environment.Exit(-1); } public static int ProgressFunc(double Complete, IntPtr Message, IntPtr Data) { Console.Write("Processing ... " + Complete * 100 + "% Completed."); if (Message != IntPtr.Zero) Console.Write(" Message:" + System.Runtime.InteropServices.Marshal.PtrToStringAnsi(Message)); if (Data != IntPtr.Zero) Console.Write(" Data:" + System.Runtime.InteropServices.Marshal.PtrToStringUni(Data)); Console.WriteLine(""); return 1; } private static RIOResampleAlg resampleAlg = RIOResampleAlg.GRIORA_NearestNeighbour; private static int argVersion = 1; private static double scale = 0.5; public static void Main(string[] args) { if (args.Length < 2) usage(); // Using early initialization of System.Console Console.WriteLine(""); try { /* -------------------------------------------------------------------- */ /* Register driver(s). */ /* -------------------------------------------------------------------- */ Gdal.AllRegister(); /* -------------------------------------------------------------------- */ /* Open dataset. */ /* -------------------------------------------------------------------- */ Dataset ds = Gdal.Open( args[0], Access.GA_ReadOnly ); if (ds == null) { Console.WriteLine("Can't open " + args[0]); System.Environment.Exit(-1); } Console.WriteLine("Raster dataset parameters:"); Console.WriteLine(" Projection: " + ds.GetProjectionRef()); Console.WriteLine(" RasterCount: " + ds.RasterCount); Console.WriteLine(" RasterSize (" + ds.RasterXSize + "," + ds.RasterYSize + ")"); /* -------------------------------------------------------------------- */ /* Get driver */ /* -------------------------------------------------------------------- */ Driver drv = ds.GetDriver(); if (drv == null) { Console.WriteLine("Can't get driver."); System.Environment.Exit(-1); } Console.WriteLine("Using driver " + drv.LongName); if (args.Length > 2) scale = double.Parse(args[2]); if (args.Length > 3) argVersion = int.Parse(args[3]); if (args.Length > 4) resampleAlg = (RIOResampleAlg)Enum.Parse(typeof(RIOResampleAlg), args[4]); /* -------------------------------------------------------------------- */ /* Processing the raster */ /* -------------------------------------------------------------------- */ SaveBitmapDirect(args[1], ds, 0, 0, ds.RasterXSize, ds.RasterYSize, Convert.ToInt32(scale * ds.RasterXSize), Convert.ToInt32(scale * ds.RasterYSize)); } catch (Exception e) { Console.WriteLine("Application error: " + e.Message); } } private static void SaveBitmapDirect(string filename, Dataset ds, int xOff, int yOff, int width, int height, int imageWidth, int imageHeight) { if (ds.RasterCount == 0) return; int[] bandMap = new int[4] { 1, 1, 1, 1 }; int channelCount = 1; bool hasAlpha = false; bool isIndexed = false; int channelSize = 8; ColorTable ct = null; // Evaluate the bands and find out a proper image transfer format for (int i = 0; i < ds.RasterCount; i++) { Band band = ds.GetRasterBand(i + 1); if (Gdal.GetDataTypeSize(band.DataType) > 8) channelSize = 16; switch (band.GetRasterColorInterpretation()) { case ColorInterp.GCI_AlphaBand: channelCount = 4; hasAlpha = true; bandMap[3] = i + 1; break; case ColorInterp.GCI_BlueBand: if (channelCount < 3) channelCount = 3; bandMap[0] = i + 1; break; case ColorInterp.GCI_RedBand: if (channelCount < 3) channelCount = 3; bandMap[2] = i + 1; break; case ColorInterp.GCI_GreenBand: if (channelCount < 3) channelCount = 3; bandMap[1] = i + 1; break; case ColorInterp.GCI_PaletteIndex: ct = band.GetRasterColorTable(); isIndexed = true; bandMap[0] = i + 1; break; case ColorInterp.GCI_GrayIndex: isIndexed = true; bandMap[0] = i + 1; break; default: // we create the bandmap using the dataset ordering by default if (i < 4 && bandMap[i] == 0) { if (channelCount < i) channelCount = i; bandMap[i] = i + 1; } break; } } // find out the pixel format based on the gathered information PixelFormat pixelFormat; DataType dataType; int pixelSpace; if (isIndexed) { pixelFormat = PixelFormat.Format8bppIndexed; dataType = DataType.GDT_Byte; pixelSpace = 1; } else { if (channelCount == 1) { if (channelSize > 8) { pixelFormat = PixelFormat.Format16bppGrayScale; dataType = DataType.GDT_Int16; pixelSpace = 2; } else { pixelFormat = PixelFormat.Format24bppRgb; channelCount = 3; dataType = DataType.GDT_Byte; pixelSpace = 3; } } else { if (hasAlpha) { if (channelSize > 8) { pixelFormat = PixelFormat.Format64bppArgb; dataType = DataType.GDT_UInt16; pixelSpace = 8; } else { pixelFormat = PixelFormat.Format32bppArgb; dataType = DataType.GDT_Byte; pixelSpace = 4; } channelCount = 4; } else { if (channelSize > 8) { pixelFormat = PixelFormat.Format48bppRgb; dataType = DataType.GDT_UInt16; pixelSpace = 6; } else { pixelFormat = PixelFormat.Format24bppRgb; dataType = DataType.GDT_Byte; pixelSpace = 3; } channelCount = 3; } } } // Create a Bitmap to store the GDAL image in Bitmap bitmap = new Bitmap(imageWidth, imageHeight, pixelFormat); if (isIndexed) { // setting up the color table if (ct != null) { int iCol = ct.GetCount(); ColorPalette pal = bitmap.Palette; for (int i = 0; i < iCol; i++) { ColorEntry ce = ct.GetColorEntry(i); pal.Entries[i] = Color.FromArgb(ce.c4, ce.c1, ce.c2, ce.c3); } bitmap.Palette = pal; } else { // grayscale ColorPalette pal = bitmap.Palette; for (int i = 0; i < 256; i++) pal.Entries[i] = Color.FromArgb(255, i, i, i); bitmap.Palette = pal; } } // Use GDAL raster reading methods to read the image data directly into the Bitmap BitmapData bitmapData = bitmap.LockBits(new Rectangle(0, 0, imageWidth, imageHeight), ImageLockMode.ReadWrite, pixelFormat); try { int stride = bitmapData.Stride; IntPtr buf = bitmapData.Scan0; using (RasterIOExtraArg arg = new RasterIOExtraArg()) { GCHandle handle = GCHandle.Alloc("Test data", GCHandleType.Pinned); try { arg.nVersion = argVersion; arg.eResampleAlg = resampleAlg; arg.pfnProgress = new Gdal.GDALProgressFuncDelegate(ProgressFunc); arg.pProgressData = handle.AddrOfPinnedObject(); // or IntPtr.Zero if not data to be added; arg.bFloatingPointWindowValidity = 0; ds.ReadRaster(xOff, yOff, width, height, buf, imageWidth, imageHeight, dataType, channelCount, bandMap, pixelSpace, stride, 1, arg); } finally { handle.Free(); } } } finally { bitmap.UnlockBits(bitmapData); } bitmap.Save(filename); } }