/// <summary>
/// returns dicomFile in the content type given by finalContentType in a HttpResponseMessage.
/// If content type is dicom, transfer syntax must be set to the given transferSyntax parameter.
/// </summary>
/// <param name="dicomFile"></param>
/// <param name="finalContentType"></param>
/// <param name="transferSyntax"></param>
/// <returns></returns>
private HttpResponseMessage ReturnImageAsHttpResponse(DicomFile dicomFile, string finalContentType, string transferSyntax)
{
MediaTypeHeaderValue header = null;
Stream streamContent = null;
if (finalContentType == JpegImageContentType)
{
DicomImage image = new DicomImage(dicomFile.Dataset);
Bitmap bmp = image.RenderImage(0).As<Bitmap>();
//When an image/jpeg MIME type is returned, the image shall be encoded using the JPEG baseline lossy 8
//bit Huffman encoded non-hierarchical non-sequential process ISO/IEC 10918.
//TODO Is it the case with default Jpeg format from Bitmap?
header = new MediaTypeHeaderValue(JpegImageContentType);
streamContent = new MemoryStream();
bmp.Save(streamContent, ImageFormat.Jpeg);
streamContent.Seek(0, SeekOrigin.Begin);
}
else if (finalContentType == AppDicomContentType)
{
//By default, the transfer syntax shall be
//"Explicit VR Little Endian".
//Note: This implies that retrieved images are sent un-compressed by default.
DicomTransferSyntax requestedTransferSyntax = DicomTransferSyntax.ExplicitVRLittleEndian;
if (transferSyntax != null)
requestedTransferSyntax = GetTransferSyntaxFromString(transferSyntax);
bool transferSyntaxIsTheSameAsSourceFile =
dicomFile.FileMetaInfo.TransferSyntax == requestedTransferSyntax;
//we only change transfer syntax if we need to
DicomFile dicomFileToStream;
if (!transferSyntaxIsTheSameAsSourceFile)
{
dicomFileToStream = dicomFile.ChangeTransferSyntax(requestedTransferSyntax);
}
else
{
dicomFileToStream = dicomFile;
}
header = new MediaTypeHeaderValue(AppDicomContentType);
streamContent = new MemoryStream();
dicomFileToStream.Save(streamContent);
streamContent.Seek(0, SeekOrigin.Begin);
}
HttpResponseMessage result = new HttpResponseMessage(HttpStatusCode.OK);
result.Content = new StreamContent(streamContent);
result.Content.Headers.ContentType = header;
return result;
}
/// <summary>
/// Convert the byte data retrieved from DCM file to Image
/// </summary>
/// <param name="imagedata"></param>
/// <returns></returns>
private Bitmap ConvertDCMData2BitImage(DicomFile dcm)
{
DicomFile newDcmFile = null;
if (dcm.FileMetaInfo.TransferSyntax.IsEncapsulated)//if the data is compressed
{
// System.Reflection.Assembly.LoadFrom(Path.Combine(Application.StartupPath,"Dicom.Native64.dll"));
DicomTranscoder.LoadCodecs(Application.StartupPath, "Dicom.Native*.dll");
newDcmFile=dcm.ChangeTransferSyntax(DicomTransferSyntax.ExplicitVRLittleEndian,new DicomJpegLsParams());
}
DicomImage imageDcm=null;
if (newDcmFile != null)
imageDcm = new DicomImage(newDcmFile.Dataset);
else
imageDcm = new DicomImage(dcm.Dataset);
DicomDataset dataset = dcm.Dataset;
byte[] fs = imageDcm.PixelData.NumberOfFrames < 2 ? imageDcm.PixelData.GetFrame(0).Data : imageDcm.PixelData.GetFrame(1).Data;
uint size = (uint)Marshal.SizeOf(typeof(short));
uint padding = (uint)fs.Length % size;
uint count = (uint)fs.Length / size;
short[] values = new short[count];
System.Buffer.BlockCopy(fs, 0, values, 0, (int)(fs.Length - padding));
int height = dataset.Get<int>(DicomTag.Rows);
int width = dataset.Get<int>(DicomTag.Columns);
int windowsWidth = (int)dataset.Get<double>(DicomTag.WindowWidth);
int windowsCenter = (int)dataset.Get<double>(DicomTag.WindowCenter);
//if the windowsWidth = 0, the DCM file is not standard type.
if (windowsWidth == 0 || windowsCenter==0)
{
windowsWidth = values.Max<short>()-values.Min<short>();
windowsCenter = windowsWidth / 2;
}
int low = windowsCenter - windowsWidth / 2;
int high = windowsCenter + windowsWidth / 2;
Bitmap bitmap = new Bitmap(width, height);
for (int i = 0; i < height; ++i)
{
for (int j = 0; j < width; ++j)
{
int r, g, b;
int temp = (int)values[(width - j - 1) * height + i];
int val = temp > high ? 255 : (temp < low ? 0 : ((temp - low) * 255 / windowsWidth));
r = g = b = val;
bitmap.SetPixel(i, width-j-1, Color.FromArgb(r, g, b));
}
}
return bitmap;
}
