orthanc: Core/DicomFormat/DicomMap.cpp comparison

comparison Core/DicomFormat/DicomMap.cpp @ 2007:655489d9165d

DicomMap::ParseDicomMetaInformation()

author	Sebastien Jodogne <s.jodogne@gmail.com>
date	Thu, 09 Jun 2016 15:46:33 +0200
parents	b1291df2f780
children	dc82c754dcaa

comparison

equal deleted inserted replaced

-:6301bbcbcaed
+:655489d9165d
 #include "DicomMap.h"
 #include <stdio.h>
 #include <memory>
 #include "DicomArray.h"
+#include "../Endianness.h"
 #include "../OrthancException.h"
 namespace Orthanc
 {
 {
 result.Clear();
 for (size_t i = 0; i < count; i++)
 {
-result.SetValue(tags[i], "");
+result.SetValue(tags[i], "", false);
 }
 }
 void DicomMap::SetupFindPatientTemplate(DicomMap& result)
 {
 }
 void DicomMap::SetupFindStudyTemplate(DicomMap& result)
 {
 SetupFindTemplate(result, studyTags, sizeof(studyTags) / sizeof(DicomTag));
-result.SetValue(DICOM_TAG_ACCESSION_NUMBER, "");
+result.SetValue(DICOM_TAG_ACCESSION_NUMBER, "", false);
-result.SetValue(DICOM_TAG_PATIENT_ID, "");
+result.SetValue(DICOM_TAG_PATIENT_ID, "", false);
 // These main DICOM tags are only indirectly related to the
 // General Study Module, remove them
 result.Remove(DICOM_TAG_INSTITUTION_NAME);
 result.Remove(DICOM_TAG_REQUESTING_PHYSICIAN);
 }
 void DicomMap::SetupFindSeriesTemplate(DicomMap& result)
 {
 SetupFindTemplate(result, seriesTags, sizeof(seriesTags) / sizeof(DicomTag));
-result.SetValue(DICOM_TAG_ACCESSION_NUMBER, "");
+result.SetValue(DICOM_TAG_ACCESSION_NUMBER, "", false);
-result.SetValue(DICOM_TAG_PATIENT_ID, "");
+result.SetValue(DICOM_TAG_PATIENT_ID, "", false);
-result.SetValue(DICOM_TAG_STUDY_INSTANCE_UID, "");
+result.SetValue(DICOM_TAG_STUDY_INSTANCE_UID, "", false);
 // These tags are considered as "main" by Orthanc, but are not in the Series module
 result.Remove(DicomTag(0x0008, 0x0070));  // Manufacturer
 result.Remove(DicomTag(0x0008, 0x1010));  // Station name
 result.Remove(DicomTag(0x0018, 0x0024));  // Sequence name
 }
 void DicomMap::SetupFindInstanceTemplate(DicomMap& result)
 {
 SetupFindTemplate(result, instanceTags, sizeof(instanceTags) / sizeof(DicomTag));
-result.SetValue(DICOM_TAG_ACCESSION_NUMBER, "");
+result.SetValue(DICOM_TAG_ACCESSION_NUMBER, "", false);
-result.SetValue(DICOM_TAG_PATIENT_ID, "");
+result.SetValue(DICOM_TAG_PATIENT_ID, "", false);
-result.SetValue(DICOM_TAG_STUDY_INSTANCE_UID, "");
+result.SetValue(DICOM_TAG_STUDY_INSTANCE_UID, "", false);
-result.SetValue(DICOM_TAG_SERIES_INSTANCE_UID, "");
+result.SetValue(DICOM_TAG_SERIES_INSTANCE_UID, "", false);
 }
 void DicomMap::CopyTagIfExists(const DicomMap& source,
 const DicomTag& tag)
 it != map_.end(); ++it)
 {
 tags.insert(it->first);
 }
 }
+static uint16_t ReadUnsignedInteger16(const char* dicom)
+{
+return le16toh(*reinterpret_cast<const uint16_t*>(dicom));
+}
+static uint32_t ReadUnsignedInteger32(const char* dicom)
+{
+return le32toh(*reinterpret_cast<const uint32_t*>(dicom));
+}
+static bool ValidateTag(const ValueRepresentation& vr,
+const std::string& value)
+{
+switch (vr)
+{
+case ValueRepresentation_ApplicationEntity:
+return value.size() <= 16;
+case ValueRepresentation_AgeString:
+return (value.size() == 4 &&
+isdigit(value[0]) &&
+isdigit(value[1]) &&
+isdigit(value[2]) &&
+(value[3] == 'D' || value[3] == 'W' || value[3] == 'M' || value[3] == 'Y'));
+case ValueRepresentation_AttributeTag:
+return value.size() == 4;
+case ValueRepresentation_CodeString:
+return value.size() <= 16;
+case ValueRepresentation_Date:
+return value.size() <= 18;
+case ValueRepresentation_DecimalString:
+return value.size() <= 16;
+case ValueRepresentation_DateTime:
+return value.size() <= 54;
+case ValueRepresentation_FloatingPointSingle:
+return value.size() == 4;
+case ValueRepresentation_FloatingPointDouble:
+return value.size() == 8;
+case ValueRepresentation_IntegerString:
+return value.size() <= 12;
+case ValueRepresentation_LongString:
+return value.size() <= 64;
+case ValueRepresentation_LongText:
+return value.size() <= 10240;
+case ValueRepresentation_OtherByte:
+return true;
+case ValueRepresentation_OtherDouble:
+return value.size() <= static_cast<size_t>((1llu << 32) - 8);
+case ValueRepresentation_OtherFloat:
+return value.size() <= static_cast<size_t>((1llu << 32) - 4);
+case ValueRepresentation_OtherLong:
+return true;
+case ValueRepresentation_OtherWord:
+return true;
+case ValueRepresentation_PersonName:
+return true;
+case ValueRepresentation_ShortString:
+return value.size() <= 16;
+case ValueRepresentation_SignedLong:
+return value.size() == 4;
+case ValueRepresentation_Sequence:
+return true;
+case ValueRepresentation_SignedShort:
+return value.size() == 2;
+case ValueRepresentation_ShortText:
+return value.size() <= 1024;
+case ValueRepresentation_Time:
+return value.size() <= 28;
+case ValueRepresentation_UnlimitedCharacters:
+return value.size() <= static_cast<size_t>((1llu << 32) - 2);
+case ValueRepresentation_UniqueIdentifier:
+return value.size() <= 64;
+case ValueRepresentation_UnsignedLong:
+return value.size() == 4;
+case ValueRepresentation_Unknown:
+return true;
+case ValueRepresentation_UniversalResource:
+return value.size() <= static_cast<size_t>((1llu << 32) - 2);
+case ValueRepresentation_UnsignedShort:
+return value.size() == 2;
+case ValueRepresentation_UnlimitedText:
+return value.size() <= static_cast<size_t>((1llu << 32) - 2);
+default:
+// Assume unsupported tags are OK
+return true;
+}
+}
+static void RemoveTagPadding(std::string& value,
+const ValueRepresentation& vr)
+{
+/**
+* Remove padding from character strings, if need be. For the time
+* being, only the UI VR is supported.
+* http://dicom.nema.org/medical/dicom/current/output/chtml/part05/sect_6.2.html
+**/
+switch (vr)
+{
+case ValueRepresentation_UniqueIdentifier:
+{
+/**
+* "Values with a VR of UI shall be padded with a single
+* trailing NULL (00H) character when necessary to achieve even
+* length."
+**/
+if (!value.empty() &&
+value[value.size() - 1] == '\0')
+{
+value.resize(value.size() - 1);
+}
+break;
+}
+/**
+* TODO implement other VR
+**/
+default:
+// No padding is applicable to this VR
+break;
+}
+}
+static bool ReadNextTag(DicomTag& tag,
+ValueRepresentation& vr,
+std::string& value,
+const char* dicom,
+size_t size,
+size_t& position)
+{
+/**
+* http://dicom.nema.org/medical/dicom/current/output/chtml/part05/chapter_7.html#sect_7.1.2
+* This function reads a data element with Explicit VR encoded using Little-Endian.
+**/
+if (position + 6 > size)
+{
+return false;
+}
+tag = DicomTag(ReadUnsignedInteger16(dicom + position),
+ReadUnsignedInteger16(dicom + position + 2));
+vr = StringToValueRepresentation(std::string(dicom + position + 4, 2), true);
+if (vr == ValueRepresentation_NotSupported)
+{
+return false;
+}
+if (vr == ValueRepresentation_OtherByte ||
+vr == ValueRepresentation_OtherDouble ||
+vr == ValueRepresentation_OtherFloat ||
+vr == ValueRepresentation_OtherLong ||
+vr == ValueRepresentation_OtherWord ||
+vr == ValueRepresentation_Sequence ||
+vr == ValueRepresentation_UnlimitedCharacters ||
+vr == ValueRepresentation_UniversalResource ||
+vr == ValueRepresentation_UnlimitedText ||
+vr == ValueRepresentation_Unknown)    // Note that "UN" should never appear in the Meta Information
+{
+if (position + 12 > size)
+{
+return false;
+}
+uint32_t length = ReadUnsignedInteger32(dicom + position + 8);
+if (position + 12 + length > size)
+{
+return false;
+}
+value.assign(dicom + position + 12, length);
+position += (12 + length);
+}
+else
+{
+if (position + 8 > size)
+{
+return false;
+}
+uint16_t length = ReadUnsignedInteger16(dicom + position + 6);
+if (position + 8 + length > size)
+{
+return false;
+}
+value.assign(dicom + position + 8, length);
+position += (8 + length);
+}
+if (!ValidateTag(vr, value))
+{
+return false;
+}
+RemoveTagPadding(value, vr);
+return true;
+}
+bool DicomMap::ParseDicomMetaInformation(DicomMap& result,
+const char* dicom,
+size_t size)
+{
+/**
+* http://dicom.nema.org/medical/dicom/current/output/chtml/part10/chapter_7.html
+* According to Table 7.1-1, besides the "DICM" DICOM prefix, the
+* file preamble (i.e. dicom[0..127]) should not be taken into
+* account to determine whether the file is or is not a DICOM file.
+**/
+if (size < 132 ||
+dicom[128] != 'D' ||
+dicom[129] != 'I' ||
+dicom[130] != 'C' ||
+dicom[131] != 'M')
+{
+return false;
+}
+/**
+* The DICOM File Meta Information must be encoded using the
+* Explicit VR Little Endian Transfer Syntax
+* (UID=1.2.840.10008.1.2.1).
+**/
+result.Clear();
+// First, we read the "File Meta Information Group Length" tag
+// (0002,0000) to know where to stop reading the meta header
+size_t position = 132;
+DicomTag tag(0x0000, 0x0000);  // Dummy initialization
+ValueRepresentation vr;
+std::string value;
+if (!ReadNextTag(tag, vr, value, dicom, size, position) ||
+tag.GetGroup() != 0x0002 ||
+tag.GetElement() != 0x0000 ||
+vr != ValueRepresentation_UnsignedLong ||
+value.size() != 4)
+{
+return false;
+}
+size_t stopPosition = position + ReadUnsignedInteger32(value.c_str());
+if (stopPosition > size)
+{
+return false;
+}
+while (position < stopPosition)
+{
+if (ReadNextTag(tag, vr, value, dicom, size, position))
+{
+result.SetValue(tag, value, IsBinaryValueRepresentation(vr));
+}
+else
+{
+return false;
+}
+}
+return true;
+}
 }

Mercurial > hg > orthanc

comparison Core/DicomFormat/DicomMap.cpp @ 2007:655489d9165d