internal DicomFragmentSequence(DicomFragmentSequence attrib)
: base(attrib)
{
_isNull = attrib._isNull;
foreach (DicomFragment fragment in attrib._fragments)
{
_fragments.Add(new DicomFragment(fragment));
}
}
public DicomCompressedPixelData(DicomMessageBase msg, byte[] frameData) : base(msg)
{
_sq = new DicomFragmentSequence(DicomTags.PixelData);
AddFrameFragment(frameData);
//ByteBuffer buffer = new ByteBuffer(frameData);
//DicomFragment fragment = new DicomFragment(buffer);
//_sq.AddFragment(fragment);
NumberOfFrames = 1;
}
public void AddFrameFragment(ByteBuffer bb)
{
DicomFragmentSequence sequence = _sq;
if ((bb.Length % 2) == 1)
{
throw new DicomCodecException("Fragment being appended is incorrectly an odd length: " + bb.Length);
}
uint offset = 0;
foreach (DicomFragment fragment in sequence.Fragments)
{
offset += (8 + fragment.Length);
}
sequence.OffsetTable.Add(offset);
sequence.Fragments.Add(new DicomFragment(bb));
}
/// <summary>
/// Append a compressed pixel data fragment's worth of data. It is assumed an entire frame is
/// contained within <paramref name="data"/>.
/// </summary>
/// <param name="data">The fragment data.</param>
public void AddFrameFragment(byte[] data)
{
DicomFragmentSequence sequence = _sq;
if ((data.Length % 2) == 1)
{
throw new DicomCodecException("Fragment being appended is incorrectly an odd length: " + data.Length);
}
uint offset = 0;
foreach (DicomFragment fragment in sequence.Fragments)
{
offset += (8 + fragment.Length);
}
sequence.OffsetTable.Add(offset);
ByteBuffer buffer = new ByteBuffer();
buffer.Append(data, 0, data.Length);
sequence.Fragments.Add(new DicomFragment(buffer));
}
public override bool Equals(object obj)
{
if (obj == null || GetType() != obj.GetType())
{
return(false);
}
DicomFragmentSequence sq = (DicomFragmentSequence)obj;
if (sq.Count != this.Count)
{
return(false);
}
for (int i = 0; i < Count; i++)
{
if (!_fragments[i].Equals(sq._fragments[i]))
{
return(false);
}
}
return(true);
}
/// <summary>
/// Constructor from a <see cref="DicomUncompressedPixelData"/> instance.
/// </summary>
/// <param name="pd">The uuncompressed pixel data attribute to initialize the object from.</param>
public DicomCompressedPixelData(DicomUncompressedPixelData pd) : base(pd)
{
_sq = new DicomFragmentSequence(DicomTags.PixelData);
}
/// <summary>
/// Constructor from a <see cref="DicomAttributeCollection"/> instance.
/// </summary>
/// <param name="collection">The collection to initialize the object from.</param>
public DicomCompressedPixelData(DicomAttributeCollection collection) : base(collection)
{
_sq = (DicomFragmentSequence)collection[DicomTags.PixelData];
}
/// <summary>
/// Constructor from a <see cref="DicomMessageBase"/> instance.
/// </summary>
/// <param name="msg">The message to initialize the object from.</param>
public DicomCompressedPixelData(DicomMessageBase msg)
: base(msg)
{
_sq = (DicomFragmentSequence)msg.DataSet[DicomTags.PixelData];
}
/// <summary>
/// Get the pixel data fragments for a frame.
/// </summary>
/// <remarks>
/// <para>
/// Note that if an offset table was not included within the pixel data, this method will
/// attempt to guess which fragments are contained within a frame.
/// </para>
/// </remarks>
/// <param name="frame">The zero offset frame to get the fragments for.</param>
/// <returns>A list of fragments associated with the frame.</returns>
public List <DicomFragment> GetFrameFragments(int frame)
{
if (frame < 0 || frame >= NumberOfFrames)
{
throw new IndexOutOfRangeException("Requested frame out of range!");
}
List <DicomFragment> fragments = new List <DicomFragment>();
DicomFragmentSequence sequence = _sq;
int fragmentCount = sequence.Fragments.Count;
if (NumberOfFrames == 1)
{
foreach (DicomFragment frag in sequence.Fragments)
{
fragments.Add(frag);
}
return(fragments);
}
if (fragmentCount == NumberOfFrames)
{
fragments.Add(sequence.Fragments[frame]);
return(fragments);
}
if (sequence.HasOffsetTable && sequence.OffsetTable.Count == NumberOfFrames)
{
uint offset = sequence.OffsetTable[frame];
uint stop = 0xffffffff;
uint pos = 0;
if ((frame + 1) < NumberOfFrames)
{
stop = sequence.OffsetTable[frame + 1];
}
int i = 0;
while (pos < offset && i < fragmentCount)
{
pos += (8 + sequence.Fragments[i].Length);
i++;
}
// check for invalid offset table
if (pos != offset)
{
goto GUESS_FRAME_OFFSET;
}
while (offset < stop && i < fragmentCount)
{
fragments.Add(sequence.Fragments[i]);
offset += (8 + sequence.Fragments[i].Length);
i++;
}
return(fragments);
}
GUESS_FRAME_OFFSET:
if (sequence.Fragments.Count > 0)
{
uint fragmentSize = sequence.Fragments[0].Length;
bool allSameLength = true;
for (int i = 0; i < fragmentCount; i++)
{
if (sequence.Fragments[i].Length != fragmentSize)
{
allSameLength = false;
break;
}
}
if (allSameLength)
{
if ((fragmentCount % NumberOfFrames) != 0)
{
throw new DicomDataException("Unable to determine frame length from pixel data sequence!");
}
int count = fragmentCount / NumberOfFrames;
int start = frame * count;
for (int i = 0; i < fragmentCount; i++)
{
fragments.Add(sequence.Fragments[start + i]);
}
return(fragments);
}
else
{
// what if a single frame ends on a fragment boundary?
int count = 0;
int start = 0;
for (int i = 0; i < fragmentCount && count < frame; i++, start++)
{
if (sequence.Fragments[i].Length != fragmentSize)
{
count++;
}
}
for (int i = start; i < fragmentCount; i++)
{
fragments.Add(sequence.Fragments[i]);
if (sequence.Fragments[i].Length != fragmentSize)
{
break;
}
}
return(fragments);
}
}
return(fragments);
}