/// <summary>
/// Load media from stream.
/// </summary>
/// <param name="stream">
/// A <see cref="Stream"/> where the media data is stored.
/// </param>
/// <param name="criteria">
/// A <see cref="MediaCodecCriteria"/> that specify parameters for loading an media stream.
/// </param>
/// <returns>
/// An <see cref="Image"/> holding the media data.
/// </returns>
/// <exception cref="ArgumentNullException">
/// Exception thrown if <paramref name="stream"/> or <paramref name="criteria"/> is null.
/// </exception>
public Image Load(Stream stream, ImageCodecCriteria criteria)
{
if (stream == null)
{
throw new ArgumentNullException("stream");
}
if (criteria == null)
{
throw new ArgumentNullException("criteria");
}
const int BufferBlockSize = 4096;
byte[] buffer = new byte[stream.Length];
int bufferOffset = 0, bytesRed;
// Read the stream content
while ((bytesRed = stream.Read(buffer, bufferOffset, BufferBlockSize)) > 0)
{
bufferOffset += bytesRed;
}
GCHandle bufferHandle = GCHandle.Alloc(buffer, GCHandleType.Pinned);
try {
Gdal.FileFromMemBuffer("/vsimem/GdalLoad", buffer.Length, bufferHandle.AddrOfPinnedObject());
using (Dataset dataset = Gdal.Open("/vsimem/GdalLoad", Access.GA_ReadOnly)) {
return(Load(dataset, criteria));
}
} finally {
// Release virtual path
Gdal.Unlink("/vsimem/GdalLoad");
bufferHandle.Free();
}
}
public static Dataset ToMemDataset(this Image image, string memPath = "/vsimem/inmemfile")
{
Dataset dataset = null;
if (image == null)
{
throw new Exception("image不能为空");
}
if (memPath?.StartsWith("/vsimem/") != true)
{
throw new Exception("memPath必须以“/vsimem/”开头");
}
byte[] buffer = null;
using (MemoryStream ms = new MemoryStream())
{
var format = image.RawFormat.ToString();
if (format.Contains("[ImageFormat:"))
{
throw new Exception("image格式不正确");
}
image.Save(ms, image.RawFormat);
buffer = ms.GetBuffer();
}
Gdal.FileFromMemBuffer(memPath, buffer);
dataset = Gdal.Open(memPath, Access.GA_ReadOnly);
return(dataset);
}
public static void Main(string[] args)
{
if (args.Length != 1)
{
usage();
}
byte[] imageBuffer;
using (FileStream fs = new FileStream(args[0], FileMode.Open, FileAccess.Read))
{
using (BinaryReader br = new BinaryReader(fs))
{
long numBytes = new FileInfo(args[0]).Length;
imageBuffer = br.ReadBytes((int)numBytes);
br.Close();
fs.Close();
}
}
Gdal.AllRegister();
string memFilename = "/vsimem/inmemfile";
try
{
Gdal.FileFromMemBuffer(memFilename, imageBuffer);
Dataset ds = Gdal.Open(memFilename, Access.GA_ReadOnly);
Console.WriteLine("Raster dataset parameters:");
Console.WriteLine(" RasterCount: " + ds.RasterCount);
Console.WriteLine(" RasterSize (" + ds.RasterXSize + "," + ds.RasterYSize + ")");
Driver drv = Gdal.GetDriverByName("GTiff");
if (drv == null)
{
Console.WriteLine("Can't get driver.");
System.Environment.Exit(-1);
}
drv.CreateCopy("sample.tif", ds, 0, null, null, null);
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
finally
{
Gdal.Unlink(memFilename);
}
}