private Bitmap ReadGrayIndex(int xOffset, int yOffset, int xSize, int ySize)
{
Band firstBand;
var disposeBand = false;
if (_overview >= 0 && _overviewCount > 0)
{
firstBand = _band.GetOverview(_overview);
disposeBand = true;
}
else
{
firstBand = _band;
}
GdalExtensions.NormalizeSizeToBand(firstBand.XSize, firstBand.YSize, xOffset, yOffset, xSize, ySize, out int width, out int height);
byte[] rBuffer = firstBand.ReadBand(xOffset, yOffset, width, height, width, height);
if (disposeBand)
{
firstBand.Dispose();
}
Bitmap result = GdalExtensions.GetBitmap(width, height, rBuffer, rBuffer, rBuffer, noDataValue: NoDataValue);
rBuffer = null;
return(result);
}
private Bitmap ReadRgba(int xOffset, int yOffset, int xSize, int ySize)
{
if (Bands.Count < 4)
{
throw new GdalException("ARGB Format was indicated but there are only " + Bands.Count + " bands!");
}
Band aBand;
Band rBand;
Band gBand;
Band bBand;
var disposeBand = false;
if (_overview >= 0 && _overviewCount > 0)
{
rBand = (Bands[0] as GdalRaster <T>)._band.GetOverview(_overview);
gBand = (Bands[1] as GdalRaster <T>)._band.GetOverview(_overview);
bBand = (Bands[2] as GdalRaster <T>)._band.GetOverview(_overview);
aBand = (Bands[3] as GdalRaster <T>)._band.GetOverview(_overview);
disposeBand = true;
}
else
{
rBand = (Bands[0] as GdalRaster <T>)._band;
gBand = (Bands[1] as GdalRaster <T>)._band;
bBand = (Bands[2] as GdalRaster <T>)._band;
aBand = (Bands[3] as GdalRaster <T>)._band;
}
GdalExtensions.NormalizeSizeToBand(rBand.XSize, rBand.YSize, xOffset, yOffset, xSize, ySize, out int width, out int height);
byte[] aBuffer = aBand.ReadBand(xOffset, yOffset, width, height, width, height);
byte[] rBuffer = rBand.ReadBand(xOffset, yOffset, width, height, width, height);
byte[] gBuffer = gBand.ReadBand(xOffset, yOffset, width, height, width, height);
byte[] bBuffer = bBand.ReadBand(xOffset, yOffset, width, height, width, height);
if (disposeBand)
{
aBand.Dispose();
rBand.Dispose();
gBand.Dispose();
bBand.Dispose();
}
Bitmap result = GdalExtensions.GetBitmap(width, height, rBuffer, gBuffer, bBuffer, aBuffer, NoDataValue);
rBuffer = null;
gBuffer = null;
bBuffer = null;
aBuffer = null;
return(result);
}
private Bitmap ReadPaletteBuffered(int xOffset, int yOffset, int xSize, int ySize)
{
ColorTable ct = _band.GetRasterColorTable();
if (ct == null)
{
throw new GdalException("Image was stored with a palette interpretation but has no color table.");
}
if (ct.GetPaletteInterpretation() != PaletteInterp.GPI_RGB)
{
throw new GdalException("Only RGB palette interpretation is currently supported by this " + " plug-in, " + ct.GetPaletteInterpretation() + " is not supported.");
}
int count = ct.GetCount();
byte[][] colorTable = new byte[ct.GetCount()][];
for (int i = 0; i < count; i++)
{
using (ColorEntry ce = ct.GetColorEntry(i))
{
colorTable[i] = new[] { (byte)ce.c4, (byte)ce.c1, (byte)ce.c2, (byte)ce.c3 };
}
}
ct.Dispose();
Band firstBand;
bool disposeBand = false;
if (_overview >= 0 && _overviewCount > 0)
{
firstBand = _band.GetOverview(_overview);
disposeBand = true;
}
else
{
firstBand = _band;
}
GdalExtensions.NormalizeSizeToBand(firstBand.XSize, firstBand.YSize, xOffset, yOffset, xSize, ySize, out int width, out int height);
byte[] indexBuffer = firstBand.ReadBand(xOffset, yOffset, width, height, width, height);
if (disposeBand)
{
firstBand.Dispose();
}
byte[] rBuffer = new byte[indexBuffer.Length];
byte[] gBuffer = new byte[indexBuffer.Length];
byte[] bBuffer = new byte[indexBuffer.Length];
byte[] aBuffer = new byte[indexBuffer.Length];
for (int i = 0; i < indexBuffer.Length; i++)
{
int index = indexBuffer[i];
aBuffer[i] = colorTable[index][0];
rBuffer[i] = colorTable[index][1];
gBuffer[i] = colorTable[index][2];
bBuffer[i] = colorTable[index][3];
}
Bitmap result = GdalExtensions.GetBitmap(width, height, rBuffer, gBuffer, gBuffer, aBuffer, NoDataValue);
rBuffer = null;
gBuffer = null;
bBuffer = null;
aBuffer = null;
return(result);
}