/// <summary>
/// Sets the color table for a raster band.
/// Only works in GTiff of <see cref="Byte"/> or <see cref="UInt16"/>
/// </summary>
/// <param name="band"></param>
public static void SetColorTable(Band band)
{
var ct = new ColorTable(PaletteInterp.GPI_RGB);
var colors = new Color[] {
Color.FromArgb(150, 163, 255, 115),
Color.FromArgb(150, 38, 115, 0),
Color.FromArgb(150, 76, 230, 0),
Color.FromArgb(150, 112, 168, 0),
Color.FromArgb(150, 0, 92, 255),
Color.FromArgb(150, 197, 0, 255),
Color.FromArgb(150, 255, 170, 0),
Color.FromArgb(150, 0, 255, 197),
Color.FromArgb(150, 255, 255, 255)
};
var i = 10;
foreach (var c in colors)
{
var ce = new ColorEntry();
ce.c4 = c.A;
ce.c3 = c.B;
ce.c2 = c.G;
ce.c1 = c.R;
ct.SetColorEntry(i, ce);
i += 10;
}
band.SetRasterColorTable(ct);
}
public static Bitmap LoadImage(string file)
{
lock (locker)
{
using (var ds = OSGeo.GDAL.Gdal.Open(file, OSGeo.GDAL.Access.GA_ReadOnly))
{
// Get the GDAL Band objects from the Dataset
Band band = ds.GetRasterBand(1);
if (band == null)
{
return(null);
}
ColorTable ct = band.GetRasterColorTable();
// Create a Bitmap to store the GDAL image in
Bitmap bitmap = new Bitmap(ds.RasterXSize, ds.RasterYSize, PixelFormat.Format8bppIndexed);
// Obtaining the bitmap buffer
BitmapData bitmapData = bitmap.LockBits(new Rectangle(0, 0, ds.RasterXSize, ds.RasterYSize),
ImageLockMode.ReadWrite, PixelFormat.Format8bppIndexed);
try
{
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;
}
int stride = bitmapData.Stride;
IntPtr buf = bitmapData.Scan0;
band.ReadRaster(0, 0, ds.RasterXSize, ds.RasterYSize, buf, ds.RasterXSize, ds.RasterYSize,
DataType.GDT_Byte, 1, stride);
}
finally
{
bitmap.UnlockBits(bitmapData);
}
return(bitmap);
}
}
}
public static Bitmap LoadImage(string file)
{
lock (locker)
{
using (var ds = OSGeo.GDAL.Gdal.Open(file, OSGeo.GDAL.Access.GA_ReadOnly))
{
// 8bit geotiff - single band
if (ds.RasterCount == 1)
{
Band band = ds.GetRasterBand(1);
if (band == null)
{
return(null);
}
ColorTable ct = band.GetRasterColorTable();
PixelFormat format = PixelFormat.Format8bppIndexed;
// Create a Bitmap to store the GDAL image in
Bitmap bitmap = new Bitmap(ds.RasterXSize, ds.RasterYSize, format);
// Obtaining the bitmap buffer
BitmapData bitmapData = bitmap.LockBits(new Rectangle(0, 0, ds.RasterXSize, ds.RasterYSize),
ImageLockMode.ReadWrite, format);
try
{
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
{
}
int stride = bitmapData.Stride;
IntPtr buf = bitmapData.Scan0;
band.ReadRaster(0, 0, ds.RasterXSize, ds.RasterYSize, buf, ds.RasterXSize, ds.RasterYSize,
DataType.GDT_Byte, 1, stride);
}
finally
{
bitmap.UnlockBits(bitmapData);
}
return(bitmap);
}
{
Bitmap bitmap = new Bitmap(ds.RasterXSize, ds.RasterYSize, PixelFormat.Format32bppArgb);
if (ds.RasterCount == 3)
{
// when we load a 24bit bitmap, we need to set the alpha channel else we get nothing
using (var tmp = Graphics.FromImage(bitmap))
{
tmp.Clear(Color.White);
}
}
for (int a = 1; a <= ds.RasterCount; a++)
{
// Get the GDAL Band objects from the Dataset
Band band = ds.GetRasterBand(a);
if (band == null)
{
return(null);
}
var cint = band.GetColorInterpretation();
// Obtaining the bitmap buffer
BitmapData bitmapData = bitmap.LockBits(new Rectangle(0, 0, ds.RasterXSize, ds.RasterYSize),
ImageLockMode.ReadWrite, PixelFormat.Format32bppArgb);
try
{
int stride = bitmapData.Stride;
IntPtr buf = bitmapData.Scan0;
var buffer = new byte[ds.RasterXSize * ds.RasterYSize];
band.ReadRaster(0, 0, ds.RasterXSize, ds.RasterYSize, buffer, ds.RasterXSize,
ds.RasterYSize, 1, ds.RasterXSize);
int c = 0;
if (cint == ColorInterp.GCI_AlphaBand)
{
foreach (var b in buffer)
{
Marshal.WriteByte(buf, 3 + c * 4, (byte)b);
c++;
}
}
else if (cint == ColorInterp.GCI_RedBand)
{
foreach (var b in buffer)
{
Marshal.WriteByte(buf, 2 + c * 4, (byte)b);
c++;
}
}
else if (cint == ColorInterp.GCI_GreenBand)
{
foreach (var b in buffer)
{
Marshal.WriteByte(buf, 1 + c * 4, (byte)b);
c++;
}
}
else if (cint == ColorInterp.GCI_BlueBand)
{
foreach (var b in buffer)
{
Marshal.WriteByte(buf, 0 + c * 4, (byte)b);
c++;
}
}
else
{
}
}
finally
{
bitmap.UnlockBits(bitmapData);
}
}
//bitmap.Save("gdal.png", ImageFormat.Png);
return(bitmap);
}
}
}
return(null);
}
