private static DicomDataset Decode(
DicomDataset oldDataset,
DicomTransferSyntax outSyntax,
IDicomCodec codec,
DicomCodecParams parameters)
{
if (codec == null)
{
throw new DicomCodecException($"Decoding dataset with transfer syntax: {oldDataset.InternalTransferSyntax} is not supported.");
}
var oldPixelData = DicomPixelData.Create(oldDataset);
var newDataset = oldDataset.Clone();
newDataset.InternalTransferSyntax = outSyntax;
var newPixelData = DicomPixelData.Create(newDataset, true);
codec.Decode(oldPixelData, newPixelData, parameters);
ProcessOverlays(oldDataset, newDataset);
newDataset.RecalculateGroupLengths(false);
return(newDataset);
}
public override void Encode(
DicomPixelData oldPixelData,
DicomPixelData newPixelData,
DicomCodecParams parameters)
{
var pixelCount = oldPixelData.Width * oldPixelData.Height;
var numberOfSegments = oldPixelData.BytesAllocated * oldPixelData.SamplesPerPixel;
for (var frame = 0; frame < oldPixelData.NumberOfFrames; frame++)
{
var frameData = oldPixelData.GetFrame(frame);
var frameArray = frameData.Data;
using var encoder = new RLEEncoder();
for (var s = 0; s < numberOfSegments; s++)
{
encoder.NextSegment();
var sample = s / oldPixelData.BytesAllocated;
var sabyte = s % oldPixelData.BytesAllocated;
int pos;
int offset;
if (newPixelData.PlanarConfiguration == PlanarConfiguration.Interleaved)
{
pos = sample * oldPixelData.BytesAllocated;
offset = numberOfSegments;
}
else
{
pos = sample * oldPixelData.BytesAllocated * pixelCount;
offset = oldPixelData.BytesAllocated;
}
pos += oldPixelData.BytesAllocated - sabyte - 1;
for (var p = 0; p < pixelCount; p++)
{
if (pos >= frameArray.Length)
{
throw new InvalidOperationException("Read position is past end of frame buffer");
}
encoder.Encode(frameArray[pos]);
pos += offset;
}
encoder.Flush();
}
encoder.MakeEvenLength();
var data = encoder.GetBuffer();
newPixelData.AddFrame(data);
}
}
public override void Decode(
DicomPixelData oldPixelData,
DicomPixelData newPixelData,
DicomCodecParams parameters)
{
for (var frame = 0; frame < oldPixelData.NumberOfFrames; frame++)
{
var rleData = oldPixelData.GetFrame(frame);
// Create new frame data of even length
var frameSize = newPixelData.UncompressedFrameSize;
if ((frameSize & 1) == 1)
{
++frameSize;
}
var frameData = new MemoryByteBuffer(new byte[frameSize]);
var pixelCount = oldPixelData.Width * oldPixelData.Height;
var numberOfSegments = oldPixelData.BytesAllocated * oldPixelData.SamplesPerPixel;
var decoder = new RLEDecoder(rleData);
if (decoder.NumberOfSegments != numberOfSegments)
{
throw new InvalidOperationException("Unexpected number of RLE segments!");
}
for (var s = 0; s < numberOfSegments; s++)
{
var sample = s / newPixelData.BytesAllocated;
var sabyte = s % newPixelData.BytesAllocated;
int pos, offset;
if (newPixelData.PlanarConfiguration == PlanarConfiguration.Interleaved)
{
pos = sample * newPixelData.BytesAllocated;
offset = newPixelData.SamplesPerPixel * newPixelData.BytesAllocated;
}
else
{
pos = sample * newPixelData.BytesAllocated * pixelCount;
offset = newPixelData.BytesAllocated;
}
pos += newPixelData.BytesAllocated - sabyte - 1;
decoder.DecodeSegment(s, frameData, pos, offset);
}
newPixelData.AddFrame(frameData);
}
}
/// <summary>
/// Initializes an instance of <see cref="DicomTranscoder"/>.
/// </summary>
/// <param name="inputSyntax">Input transfer syntax.</param>
/// <param name="outputSyntax">Output transfer syntax.</param>
/// <param name="inputCodecParams">Input codec parameters.</param>
/// <param name="outputCodecParams">Output codec parameters.</param>
public DicomTranscoder(
DicomTransferSyntax inputSyntax,
DicomTransferSyntax outputSyntax,
DicomCodecParams inputCodecParams = null,
DicomCodecParams outputCodecParams = null)
{
InputSyntax = inputSyntax;
OutputSyntax = outputSyntax;
InputCodecParams = inputCodecParams ?? DefaultInputCodecParams(inputSyntax);
OutputCodecParams = outputCodecParams;
_inputCodec = new Lazy <IDicomCodec>(() => InitializeCodec(InputSyntax));
_outputCodec = new Lazy <IDicomCodec>(() => InitializeCodec(OutputSyntax));
}
private static DicomDataset Encode(
DicomDataset oldDataset,
DicomTransferSyntax outSyntax,
IDicomCodec codec,
DicomCodecParams parameters)
{
if (codec == null)
{
throw new DicomCodecException($"Encoding dataset to transfer syntax {outSyntax} is not supported.");
}
var oldPixelData = DicomPixelData.Create(oldDataset);
var newDataset = oldDataset.Clone();
newDataset.InternalTransferSyntax = outSyntax;
var newPixelData = DicomPixelData.Create(newDataset, true);
codec.Encode(oldPixelData, newPixelData, parameters);
if (outSyntax.IsLossy && newPixelData.NumberOfFrames > 0)
{
newDataset.AddOrUpdate(new DicomCodeString(DicomTag.LossyImageCompression, "01"));
var methods = new List <string>();
if (newDataset.Contains(DicomTag.LossyImageCompressionMethod))
{
methods.AddRange(newDataset.GetValues <string>(DicomTag.LossyImageCompressionMethod));
}
methods.Add(outSyntax.LossyCompressionMethod);
newDataset.AddOrUpdate(new DicomCodeString(DicomTag.LossyImageCompressionMethod, methods.ToArray()));
double oldSize = oldPixelData.GetFrame(0).Size;
double newSize = newPixelData.GetFrame(0).Size;
var ratio = string.Format(CultureInfo.InvariantCulture, "{0:0.000}", oldSize / newSize);
newDataset.AddOrUpdate(new DicomDecimalString(DicomTag.LossyImageCompressionRatio, ratio));
}
ProcessOverlays(oldDataset, newDataset);
newDataset.RecalculateGroupLengths(false);
return(newDataset);
}
public abstract void Decode(
DicomPixelData oldPixelData,
DicomPixelData newPixelData,
DicomCodecParams parameters);
