public WADOResponse Process(WADORequestTypeHandlerContext context)
{
Platform.CheckForNullReference(context, "httpContext");
Platform.CheckForNullReference(context.ServerAE, "context.ServerAE");
Platform.CheckForNullReference(context.HttpContext, "context.HttpContext");
// Cache the query string for performance purpose. Every time Request.QueryString is called, .NET will rebuild the entire dictionary.
NameValueCollection query = context.HttpContext.Request.QueryString;
ServerPartition partition = ServerPartitionMonitor.Instance.GetPartition(context.ServerAE);
if (partition == null)
{
throw new WADOException(HttpStatusCode.NotFound, String.Format(SR.FaultPartitionNotExists, context.ServerAE));
}
if (!partition.Enabled)
{
throw new WADOException(HttpStatusCode.Forbidden, String.Format(SR.FaultPartitionDisabled, context.ServerAE));
}
ImageStreamingContext streamingContext = new ImageStreamingContext(context.HttpContext);
streamingContext.ServerAE = context.ServerAE;
streamingContext.ContentType = query["ContentType"];
streamingContext.AcceptTypes = context.HttpContext.Request.AcceptTypes;
streamingContext.StudyInstanceUid = query["studyuid"];
streamingContext.SeriesInstanceUid = query["seriesuid"];
streamingContext.ObjectUid = query["objectuid"];
string sessionId = context.HttpContext.Request.RemoteEndPoint.Address.ToString();
StudyStorageLoader storageLoader = new StudyStorageLoader(sessionId);
storageLoader.CacheEnabled = ImageStreamingServerSettings.Default.EnableCache;
storageLoader.CacheRetentionTime = ImageStreamingServerSettings.Default.CacheRetentionWindow;
streamingContext.StorageLocation = storageLoader.Find(streamingContext.StudyInstanceUid, partition);
// convert the dicom image into the appropriate mime type
WADOResponse response = new WADOResponse();
IImageMimeTypeProcessor processor = GetMimeTypeProcessor(streamingContext);
MimeTypeProcessorOutput output = processor.Process(streamingContext);
response.Output = output.Output;
response.ContentType = output.ContentType;
response.IsLast = output.IsLast;
return(response);
}
public MimeTypeProcessorOutput Process(ImageStreamingContext context)
{
var output = new MimeTypeProcessorOutput
{
ContentType = OutputMimeType
};
var file = new DicomFile(context.ImagePath);
file.Load(DicomReadOptions.StorePixelDataReferences);
if (!file.SopClass.Equals(SopClass.EncapsulatedPdfStorage))
throw new WADOException(HttpStatusCode.NotImplemented, "image/pdf is not supported for this type of object: " + file.SopClass.Name);
var iod = new EncapsulatedDocumentModuleIod(file.DataSet);
output.Output = iod.EncapsulatedDocument;
return output;
}
public MimeTypeProcessorOutput Process(ImageStreamingContext context)
{
uint stopTag;
if (!uint.TryParse(context.Request.QueryString["stopTag"] ?? "", NumberStyles.HexNumber, null, out stopTag))
stopTag = DicomTags.PixelData;
if (stopTag > DicomTags.PixelData)
throw new WADOException(HttpStatusCode.BadRequest,
"Stop tag must be less than PixelData tag.");
MimeTypeProcessorOutput output = new MimeTypeProcessorOutput();
output.ContentType = OutputMimeType;
DicomFile file = new DicomFile(context.ImagePath);
file.Load(stopTag, DicomReadOptions.Default);
output.ContentType = OutputMimeType;
MemoryStream memStream = new MemoryStream();
file.Save(memStream, DicomWriteOptions.Default);
output.Output = memStream.ToArray();
return output;
}
public MimeTypeProcessorOutput Process(ImageStreamingContext context)
{
MimeTypeProcessorOutput output = new MimeTypeProcessorOutput();
output.ContentType = OutputMimeType;
using (FileStream stream = FileStreamOpener.OpenForRead(context.ImagePath, FileMode.Open))
{
output.ContentType = OutputMimeType;
byte[] buffer = new byte[stream.Length];
int offset = 0;
int readBytes = 0;
do
{
readBytes = stream.Read(buffer, offset, buffer.Length - offset);
if (readBytes > 0)
{
offset += readBytes;
}
} while (readBytes > 0);
output.Output = buffer;
stream.Close();
}
return output;
}
public MimeTypeProcessorOutput Process(ImageStreamingContext context)
{
Platform.CheckForNullReference(context, "context");
DicomPixelData pd = context.PixelData;
MimeTypeProcessorOutput output = new MimeTypeProcessorOutput();
int frame = context.FrameNumber;
if (context.FrameNumber < 0)
{
throw new WADOException(HttpStatusCode.BadRequest, String.Format("Requested FrameNumber {0} cannot be negative.", frame));
}
else if (frame >= pd.NumberOfFrames)
{
throw new WADOException(HttpStatusCode.BadRequest, String.Format("Requested FrameNumber {0} exceeds the number of frames in the image.", frame));
}
output.ContentType = OutputMimeType;
PixelDataLoader loader = new PixelDataLoader(context);
output.Output = loader.ReadFrame(frame);
output.IsLast = (pd.NumberOfFrames == frame + 1);
// note: the transfer syntax of the returned pixel data may not be the same as that in the original image.
// In the future, the clients may specify different transfer syntaxes which may mean the compressed image must be decompressed or vice versa.
TransferSyntax transferSyntax = pd.TransferSyntax;
output.IsCompressed = transferSyntax.LosslessCompressed || transferSyntax.LossyCompressed;
#region Special Code
// Note: this block of code inject special header fields to assist the clients handling the images
// For eg, the
if (output.IsLast)
context.Response.Headers.Add("IsLast", "true");
if (output.IsCompressed)
{
// Fields that can be used by the web clients to decompress the compressed images streamed by the server.
context.Response.Headers.Add("Compressed", "true");
context.Response.Headers.Add("TransferSyntaxUid", pd.TransferSyntax.UidString);
context.Response.Headers.Add("BitsAllocated", pd.BitsAllocated.ToString(CultureInfo.InvariantCulture));
context.Response.Headers.Add("BitsStored", pd.BitsStored.ToString(CultureInfo.InvariantCulture));
context.Response.Headers.Add("DerivationDescription", pd.DerivationDescription);
context.Response.Headers.Add("HighBit", pd.HighBit.ToString(CultureInfo.InvariantCulture));
context.Response.Headers.Add("ImageHeight", pd.ImageHeight.ToString(CultureInfo.InvariantCulture));
context.Response.Headers.Add("ImageWidth", pd.ImageWidth.ToString(CultureInfo.InvariantCulture));
context.Response.Headers.Add("LossyImageCompression", pd.LossyImageCompression);
context.Response.Headers.Add("LossyImageCompressionMethod", pd.LossyImageCompressionMethod);
context.Response.Headers.Add("LossyImageCompressionRatio", pd.LossyImageCompressionRatio.ToString(CultureInfo.InvariantCulture));
context.Response.Headers.Add("NumberOfFrames", pd.NumberOfFrames.ToString(CultureInfo.InvariantCulture));
context.Response.Headers.Add("PhotometricInterpretation", pd.PhotometricInterpretation);
context.Response.Headers.Add("PixelRepresentation", pd.PixelRepresentation.ToString(CultureInfo.InvariantCulture));
context.Response.Headers.Add("PlanarConfiguration", pd.PlanarConfiguration.ToString(CultureInfo.InvariantCulture));
context.Response.Headers.Add("SamplesPerPixel", pd.SamplesPerPixel.ToString(CultureInfo.InvariantCulture));
}
#endregion
if (Platform.IsLogLevelEnabled(LogLevel.Debug))
{
Platform.Log(LogLevel.Debug, "Streaming {0} pixel data: {1} x {2} x {3} , {4} bits [{5} KB] ({6})",
output.IsCompressed ? "compressed" : "uncompressed",
pd.ImageHeight,
pd.ImageWidth,
pd.SamplesPerPixel,
pd.BitsStored,
output.Output.Length/1024,
pd.TransferSyntax.Name);
}
return output;
}
