public static void WriteBitmapAsGeotiff(Bitmap bmp, Rectangle bounds, string target_path)
{
if (!GetGdalDrivers())
{
return;
}
// set up MEM driver to read bitmap data
int bandCount = 1;
int pixelOffset = 1;
DataType dataType = DataType.GDT_Byte;
int[] band2ptroffset = null;
switch (bmp.PixelFormat)
{
case PixelFormat.Format16bppGrayScale:
dataType = DataType.GDT_Int16;
bandCount = 1;
pixelOffset = 2;
break;
case PixelFormat.Format24bppRgb:
dataType = DataType.GDT_Byte;
bandCount = 3;
pixelOffset = 3;
break;
case PixelFormat.Format32bppArgb:
dataType = DataType.GDT_Byte;
//bandCount = 4; // This was the band count, but the order is wrong
bandCount = 3;
band2ptroffset = new int[] { 3, 2, 1, 0 };
pixelOffset = 4;
break;
case PixelFormat.Format48bppRgb:
dataType = DataType.GDT_UInt16;
bandCount = 3;
pixelOffset = 6;
break;
case PixelFormat.Format64bppArgb:
dataType = DataType.GDT_UInt16;
bandCount = 4;
pixelOffset = 8;
break;
case PixelFormat.Format8bppIndexed:
dataType = DataType.GDT_Byte;
bandCount = 1;
pixelOffset = 1;
break;
default:
Console.WriteLine("Invalid pixel format " + bmp.PixelFormat.ToString());
break;
}
// Use GDAL raster reading methods to read the image data directly into the Bitmap
BitmapData bitmapData = bmp.LockBits(new Rectangle(0, 0, bmp.Width, bmp.Height), ImageLockMode.ReadOnly, bmp.PixelFormat);
int stride = bitmapData.Stride;
IntPtr buf = bitmapData.Scan0;
try
{
Dataset ds = _memory_driver.Create("", bmp.Width, bmp.Height, 0, dataType, null);
var transform = GetAffineTransformOfBounds(bounds);
ds.SetGeoTransform(transform);
ds.SetProjection(ToWkt(dst_wkt));
//var color_interp = new ColorInterp[] { ColorInterp.GCI_AlphaBand, ColorInterp.GCI_RedBand, ColorInterp.GCI_GreenBand, ColorInterp.GCI_BlueBand };
// add bands in a reverse order
for (int i = 1; i <= bandCount; i++)
{
// original
CPLErr err;
if (band2ptroffset == null)
{
err = ds.AddBand(dataType, new string[] { "DATAPOINTER=" + Convert.ToString(buf.ToInt64() + bandCount - i), "PIXELOFFSET=" + pixelOffset, "LINEOFFSET=" + stride });
}
else
{
err = ds.AddBand(dataType, new string[] { "DATAPOINTER=" + Convert.ToString(buf.ToInt64() + band2ptroffset[i]), "PIXELOFFSET=" + pixelOffset, "LINEOFFSET=" + stride });
}
if (err != CPLErr.CE_None)
{
Console.WriteLine($"Error adding band to {target_path}");
}
}
if (bmp.PixelFormat == PixelFormat.Format8bppIndexed)
{
var ct1 = new ColorTable(PaletteInterp.GPI_RGB);
var band = ds.GetRasterBand(1);
var ct = band.GetRasterColorTable();
Console.WriteLine($"color table count={ct.GetCount()}");
}
if (File.Exists(target_path))
{
File.Delete(target_path);
}
var ds_copy = _geotif_driver.CreateCopy(target_path, ds, 0, null, null, null);
ds_copy.FlushCache();
ds_copy.Dispose();
ds.Dispose();
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
finally
{
bmp.UnlockBits(bitmapData);
}
}
public static void Main(string[] args)
{
if (args.Length != 1)
{
usage();
}
Gdal.AllRegister();
Bitmap bmp = new Bitmap(args[0]);
// set up MEM driver to read bitmap data
int bandCount = 1;
int pixelOffset = 1;
DataType dataType = DataType.GDT_Byte;
switch (bmp.PixelFormat)
{
case PixelFormat.Format16bppGrayScale:
dataType = DataType.GDT_Int16;
bandCount = 1;
pixelOffset = 2;
break;
case PixelFormat.Format24bppRgb:
dataType = DataType.GDT_Byte;
bandCount = 3;
pixelOffset = 3;
break;
case PixelFormat.Format32bppArgb:
dataType = DataType.GDT_Byte;
bandCount = 4;
pixelOffset = 4;
break;
case PixelFormat.Format48bppRgb:
dataType = DataType.GDT_UInt16;
bandCount = 3;
pixelOffset = 6;
break;
case PixelFormat.Format64bppArgb:
dataType = DataType.GDT_UInt16;
bandCount = 4;
pixelOffset = 8;
break;
default:
Console.WriteLine("Invalid pixel format " + bmp.PixelFormat.ToString());
break;
}
// Use GDAL raster reading methods to read the image data directly into the Bitmap
BitmapData bitmapData = bmp.LockBits(new Rectangle(0, 0, bmp.Width, bmp.Height), ImageLockMode.ReadOnly, bmp.PixelFormat);
int stride = bitmapData.Stride;
IntPtr buf = bitmapData.Scan0;
try
{
Driver drvmem = Gdal.GetDriverByName("MEM");
// create a MEM dataset
Dataset ds = drvmem.Create("", bmp.Width, bmp.Height, 0, dataType, null);
// add bands in a reverse order
for (int i = 1; i <= bandCount; i++)
{
ds.AddBand(dataType, new string[] { "DATAPOINTER=" + Convert.ToString(buf.ToInt64() + bandCount - i), "PIXELOFFSET=" + pixelOffset, "LINEOFFSET=" + stride });
}
// display parameters
Console.WriteLine("Raster dataset parameters:");
Console.WriteLine(" RasterCount: " + ds.RasterCount);
Console.WriteLine(" RasterSize (" + ds.RasterXSize + "," + ds.RasterYSize + ")");
// write dataset to tif file
Driver drv = Gdal.GetDriverByName("GTiff");
if (drv == null)
{
Console.WriteLine("Can't get driver.");
System.Environment.Exit(-1);
}
drv.CreateCopy("sample2.tif", ds, 0, null, null, null);
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
finally
{
bmp.UnlockBits(bitmapData);
}
}
