public static ImageDecoderEnumerator CreateDecoderEnumerator(
IImagingConfig imagingConfig,
Stream stream,
DecoderOptions?decoderOptions = null,
CancellationToken cancellationToken = default)
{
if (imagingConfig == null)
{
throw new ArgumentNullException(nameof(imagingConfig));
}
var prefixStream = imagingConfig.CreateStreamWithHeaderPrefix(stream);
Memory <byte> prefix = prefixStream.GetPrefix(cancellationToken);
ImageFormat? format = DetectFormat(imagingConfig, prefix.Span);
if (format == null)
{
if (prefix.Length == 0)
{
throw new UnknownImageFormatException(
"No bytes were read from the stream.");
}
else
{
throw new UnknownImageFormatException(
$"Failed to recognize any format from the first {prefix.Length} bytes.");
}
}
IImageDecoder decoder = imagingConfig.CreateDecoder(prefixStream, format, decoderOptions);
return(new ImageDecoderEnumerator(decoder, cancellationToken));
}
public static ImageInfo Identify(
IImagingConfig config, Stream stream, CancellationToken cancellationToken = default)
{
using var prefixedStream = config.CreateStreamWithHeaderPrefix(stream);
Memory <byte> prefix = prefixedStream.GetPrefix(cancellationToken);
ImageFormat?format = DetectFormat(config, prefix.Span);
if (format == null)
{
throw new UnknownImageFormatException();
}
var infoDetector = config.GetInfoDetector(format);
return(infoDetector.Identify(config, prefixedStream, cancellationToken));
}
