1 /*=========================================================================
4 Module: $RCSfile: gdcmDocument.cxx,v $
6 Date: $Date: 2006/01/27 10:01:33 $
7 Version: $Revision: 1.336 $
9 Copyright (c) CREATIS (Centre de Recherche et d'Applications en Traitement de
10 l'Image). All rights reserved. See Doc/License.txt or
11 http://www.creatis.insa-lyon.fr/Public/Gdcm/License.html for details.
13 This software is distributed WITHOUT ANY WARRANTY; without even
14 the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
15 PURPOSE. See the above copyright notices for more information.
17 =========================================================================*/
19 #include "gdcmDocument.h"
20 #include "gdcmSeqEntry.h"
21 #include "gdcmGlobal.h"
23 #include "gdcmDebug.h"
25 #include "gdcmDictSet.h"
26 #include "gdcmDocEntrySet.h"
27 #include "gdcmSQItem.h"
28 #include "gdcmDataEntry.h"
33 #include <ctype.h> // for isdigit
34 #include <stdlib.h> // for atoi
36 #if defined(__BORLANDC__)
37 #include <mem.h> // for memset
42 //-----------------------------------------------------------------------------
44 // Refer to Document::SetMaxSizeLoadEntry()
45 const unsigned int Document::MAX_SIZE_LOAD_ELEMENT_VALUE = 0xfff; // 4096
47 //-----------------------------------------------------------------------------
48 // Constructor / Destructor
49 // Constructors and destructors are protected to avoid user to invoke directly
52 * \brief This default constructor neither loads nor parses the file.
53 * You should then invoke \ref Document::Load.
61 SetMaxSizeLoadEntry(MAX_SIZE_LOAD_ELEMENT_VALUE);
64 Filetype = ExplicitVR;
65 // Load will set it to true if sucessfull
66 Group0002Parsed = false;
67 IsDocumentAlreadyLoaded = false;
68 IsDocumentModified = true;
69 LoadMode = LD_ALL; // default : load everything, later
74 * \brief Canonical destructor.
76 Document::~Document ()
81 //-----------------------------------------------------------------------------
84 * \brief Loader. use SetLoadMode(), SetFileName() before !
85 * @return false if file cannot be open or no swap info was found,
86 * or no tag was found.
88 bool Document::Load( )
90 if ( GetFileName() == "" )
92 gdcmWarningMacro( "Use SetFileName, before !" );
95 return DoTheLoadingDocumentJob( );
99 * \brief Performs the Loading Job (internal use only)
100 * @return false if file cannot be open or no swap info was found,
101 * or no tag was found.
103 bool Document::DoTheLoadingDocumentJob( )
105 if ( ! IsDocumentModified ) // Nothing to do !
113 // warning already performed in OpenFile()
118 Group0002Parsed = false;
120 gdcmDebugMacro( "Starting parsing of file: " << Filename.c_str());
122 Fp->seekg(0, std::ios::end);
123 long lgt = Fp->tellg(); // total length of the file
125 Fp->seekg(0, std::ios::beg);
127 // CheckSwap returns a boolean
128 // (false if no swap info of any kind was found)
131 gdcmWarningMacro( "Neither a DICOM V3 nor an ACR-NEMA file: "
132 << Filename.c_str());
137 long beg = Fp->tellg(); // just after DICOM preamble (if any)
139 lgt -= beg; // remaining length to parse
142 // Loading is done during parsing
143 ParseDES( this, beg, lgt, false); // delim_mode is first defaulted to false
147 gdcmErrorMacro( "No tag in internal hash table for: "
148 << Filename.c_str());
152 IsDocumentAlreadyLoaded = true;
154 Fp->seekg( 0, std::ios::beg);
156 // Load 'non string' values
158 std::string PhotometricInterpretation = GetEntryString(0x0028,0x0004);
159 if ( PhotometricInterpretation == "PALETTE COLOR " )
162 // Probabely this line should be outside the 'if'
163 // Try to find an image sample holding a 'gray LUT'
164 LoadEntryBinArea(0x0028,0x1200); // gray LUT
167 /// --> FIXME : The difference between BinEntry and DataEntry
168 /// --> no longer exists, but the alteration of Dicom Dictionary remains.
169 /// --> Old comment restored on purpose.
170 /// --> New one (replacing both BinEntry and ValEntry by DataEntry)
171 /// --> had absolutely no meaning.
172 /// --> The whole comment will be removed when the stuff is cleaned !
174 /// The tags refered by the three following lines used to be CORRECTLY
175 /// defined as having an US Value Representation in the public
176 /// dictionary. BUT the semantics implied by the three following
177 /// lines state that the corresponding tag contents are in fact
178 /// the ones of a BinEntry.
179 /// In order to fix things "Quick and Dirty" the dictionary was
180 /// altered on PURPOSE but now contains a WRONG value.
181 /// In order to fix things and restore the dictionary to its
182 /// correct value, one needs to decide of the semantics by deciding
183 /// whether the following tags are either :
184 /// - multivaluated US, and hence loaded as ValEntry, but afterwards
185 /// also used as BinEntry, which requires the proper conversion,
186 /// - OW, and hence loaded as BinEntry, but afterwards also used
187 /// as ValEntry, which requires the proper conversion.
189 // --> OB (byte aray) or OW (short int aray)
190 // The actual VR has to be deduced from other entries.
191 // Our way of loading them may fail in some cases :
192 // We must or not SwapByte depending on other field values.
194 LoadEntryBinArea(0x0028,0x1201); // R LUT
195 LoadEntryBinArea(0x0028,0x1202); // G LUT
196 LoadEntryBinArea(0x0028,0x1203); // B LUT
198 // Segmented Red Palette Color LUT Data
199 LoadEntryBinArea(0x0028,0x1221);
200 // Segmented Green Palette Color LUT Data
201 LoadEntryBinArea(0x0028,0x1222);
202 // Segmented Blue Palette Color LUT Data
203 LoadEntryBinArea(0x0028,0x1223);
206 //FIXME later : how to use it?
207 SeqEntry *modLutSeq = GetSeqEntry(0x0028,0x3000);
210 SQItem *sqi= modLutSeq->GetFirstSQItem();
213 DataEntry *dataEntry = sqi->GetDataEntry(0x0028,0x3006);
214 if ( dataEntry != 0 )
216 if ( dataEntry->GetLength() != 0 )
218 // FIXME : CTX dependent means : contexted dependant.
219 // see upper comment.
220 LoadEntryBinArea(dataEntry); //LUT Data (CTX dependent)
226 // Force Loading some more elements if user asked to.
229 for (ListElements::iterator it = UserForceLoadList.begin();
230 it != UserForceLoadList.end();
233 gdcmDebugMacro( "Force Load " << std::hex
234 << (*it).Group << "|" <<(*it).Elem );
236 d = GetDocEntry( (*it).Group, (*it).Elem);
240 gdcmWarningMacro( "You asked toForce Load " << std::hex
241 << (*it).Group <<"|"<< (*it).Elem
242 << " that doesn't exist" );
246 LoadDocEntry(d, true);
251 // ----------------------------
252 // Specific code to allow gdcm to read ACR-LibIDO formated images
253 // Note: ACR-LibIDO is an extension of the ACR standard that was
254 // used at CREATIS. For the time being (say a couple of years)
255 // we keep this kludge to allow CREATIS users
256 // reading their old images.
258 // if recognition code tells us we deal with a LibIDO image
259 // we switch lineNumber and columnNumber
262 RecCode = GetEntryString(0x0008, 0x0010); // recognition code (RET)
263 if (RecCode == "ACRNEMA_LIBIDO_1.1" ||
264 RecCode == "CANRME_AILIBOD1_1." ) // for brain-damaged softwares
265 // with "little-endian strings"
267 Filetype = ACR_LIBIDO;
268 std::string rows = GetEntryString(0x0028, 0x0010);
269 std::string columns = GetEntryString(0x0028, 0x0011);
270 SetEntryString(columns, 0x0028, 0x0010);
271 SetEntryString(rows , 0x0028, 0x0011);
273 // --- End of ACR-LibIDO kludge ---
279 * \brief Adds a new element we want to load anyway
280 * @param group Group number of the target tag.
281 * @param elem Element number of the target tag.
283 void Document::AddForceLoadElement (uint16_t group, uint16_t elem)
288 UserForceLoadList.push_back(el);
291 * \brief Get the public dictionary used
293 Dict *Document::GetPubDict()
299 * \brief Get the shadow dictionary used
301 Dict *Document::GetShaDict()
307 * \brief Set the shadow dictionary used
308 * @param dict dictionary to use in shadow
310 bool Document::SetShaDict(Dict *dict)
317 * \brief Set the shadow dictionary used
318 * @param dictName name of the dictionary to use in shadow
320 bool Document::SetShaDict(DictKey const &dictName)
322 RefShaDict = Global::GetDicts()->GetDict(dictName);
327 * \brief This predicate tells us whether or not the current Document
328 * was properly parsed and contains at least *one* Dicom Element
329 * (and nothing more, sorry).
330 * @return false when we're 150 % sure it's NOT a Dicom/Acr file,
333 bool Document::IsParsable()
335 if ( Filetype == Unknown )
337 gdcmWarningMacro( "Wrong filetype for " << GetFileName());
343 gdcmWarningMacro( "No tag in internal hash table.");
350 * \brief This predicate tells us whether or not the current Document
351 * was properly parsed and contains at least *one* Dicom Element
352 * (and nothing more, sorry).
353 * @return false when we're 150 % sure it's NOT a Dicom/Acr file,
356 bool Document::IsReadable()
362 * \brief Predicate for dicom version 3 file.
363 * @return True when the file is a dicom version 3.
365 bool Document::IsDicomV3()
367 // Checking if Transfer Syntax exists is enough
368 // Anyway, it's too late check if the 'Preamble' was found ...
369 // And ... would it be a rich idea to check ?
370 // (some 'no Preamble' DICOM images exist !)
371 return GetDocEntry(0x0002, 0x0010) != NULL;
375 * \brief Predicate for Papyrus file
376 * Dedicated to whomsoever it may concern
377 * @return True when the file is a Papyrus file.
379 bool Document::IsPapyrus()
381 // check for Papyrus private Sequence
382 DocEntry *e = GetDocEntry(0x0041, 0x1050);
385 // check if it's actually a Sequence
386 if ( !dynamic_cast<SeqEntry*>(e) )
392 * \brief returns the File Type
393 * (ACR, ACR_LIBIDO, ExplicitVR, ImplicitVR, Unknown)
394 * @return the FileType code
396 FileType Document::GetFileType()
402 * \brief Accessor to the Transfer Syntax (when present) of the
403 * current document (it internally handles reading the
404 * value from disk when only parsing occured).
405 * @return The encountered Transfer Syntax of the current document, if DICOM.
406 * GDCM_UNKNOWN for ACR-NEMA files (or broken headers ...)
408 std::string Document::GetTransferSyntax()
410 DocEntry *entry = GetDocEntry(0x0002, 0x0010);
416 // The entry might be present but not loaded (parsing and loading
417 // happen at different stages): try loading and proceed with check...
418 LoadDocEntrySafe(entry);
419 if (DataEntry *dataEntry = dynamic_cast<DataEntry *>(entry) )
421 std::string transfer = dataEntry->GetString();
422 // The actual transfer (as read from disk) might be padded. We
423 // first need to remove the potential padding. We can make the
424 // weak assumption that padding was not executed with digits...
425 if ( transfer.length() == 0 )
427 // for brain damaged headers
428 gdcmWarningMacro( "Transfer Syntax has length = 0.");
431 while ( !isdigit((unsigned char)transfer[transfer.length()-1]) )
433 transfer.erase(transfer.length()-1, 1);
434 if ( transfer.length() == 0 )
436 // for brain damaged headers
437 gdcmWarningMacro( "Transfer Syntax contains no valid character.");
447 * \brief Accesses the info from 0002,0010 : Transfer Syntax and TS
448 * @return The full Transfer Syntax Name (as opposed to Transfer Syntax UID)
450 std::string Document::GetTransferSyntaxName()
452 // use the TS (TS : Transfer Syntax)
453 std::string transferSyntax = GetEntryString(0x0002,0x0010);
455 if ( (transferSyntax.find(GDCM_NOTLOADED) < transferSyntax.length()) )
457 gdcmErrorMacro( "Transfer Syntax not loaded. " << std::endl
458 << "Better you increase MAX_SIZE_LOAD_ELEMENT_VALUE" );
459 return "Uncompressed ACR-NEMA";
461 if ( transferSyntax == GDCM_UNFOUND )
463 gdcmDebugMacro( "Unfound Transfer Syntax (0002,0010)");
464 return "Uncompressed ACR-NEMA";
467 // we do it only when we need it
468 const TSKey &tsName = Global::GetTS()->GetValue( transferSyntax );
470 // Global::GetTS() is a global static you shall never try to delete it!
474 // --------------- Swap Code ------------------
476 * \brief Swaps the bytes so they agree with the processor order
477 * @return The properly swaped 16 bits integer.
479 uint16_t Document::SwapShort(uint16_t a)
481 if ( SwapCode == 4321 || SwapCode == 2143 )
483 //a = ((( a << 8 ) & 0xff00 ) | (( a >> 8 ) & 0x00ff ) );
485 a = ( a << 8 ) | ( a >> 8 );
491 * \brief Swaps back the bytes of 4-byte long integer accordingly to
493 * @return The properly swaped 32 bits integer.
495 uint32_t Document::SwapLong(uint32_t a)
502 // a=( ((a<<24) & 0xff000000) | ((a<<8) & 0x00ff0000) |
503 // ((a>>8) & 0x0000ff00) | ((a>>24) & 0x000000ff) );
505 a=( ( a<<24) | ((a<<8) & 0x00ff0000) |
506 ((a>>8) & 0x0000ff00) | (a>>24) );
509 // a=( ((a<<16) & 0xffff0000) | ((a>>16) & 0x0000ffff) );
510 a=( (a<<16) | (a>>16) );
513 a=( ((a<< 8) & 0xff00ff00) | ((a>>8) & 0x00ff00ff) );
516 gdcmErrorMacro( "Unexpected swap code:" << SwapCode );
523 * \brief Swaps back the bytes of 8-byte long 'double' accordingly to
525 * @return The properly swaped 64 bits double.
527 double Document::SwapDouble(double a)
531 // There were no 'double' at ACR-NEMA time.
532 // We just have to deal with 'straight Little Endian' and
533 // 'straight Big Endian'
538 char *beg = (char *)&a;
541 for (unsigned int i = 0; i<7; i++)
552 gdcmErrorMacro( "Unexpected swap code:" << SwapCode );
559 // -----------------File I/O ---------------
561 * \brief Tries to open the file \ref Document::Filename and
562 * checks the preamble when existing.
563 * @return The FILE pointer on success.
565 std::ifstream *Document::OpenFile()
567 HasDCMPreamble = false;
568 if (Filename.length() == 0)
575 gdcmDebugMacro( "File already open: " << Filename.c_str());
579 Fp = new std::ifstream(Filename.c_str(), std::ios::in | std::ios::binary);
582 // Don't user gdcmErrorMacro :
583 // a spurious message will appear when you use, for instance
584 // gdcm::FileHelper *fh = new gdcm::FileHelper( outputFileName );
585 // to create outputFileName.
587 // FIXME : if the upper comment is still usefull
588 // --> the constructor is not so good ...
590 gdcmWarningMacro( "Cannot open file: " << Filename.c_str());
594 //exit(1); // No function is allowed to leave the application instead
595 // of warning the caller
599 Fp->read((char*)&zero, (size_t)2);
606 //-- Broken ACR or DICOM with no Preamble; may start with a Shadow Group --
608 // FIXME : We cannot be sure the preable is only zeroes..
609 // (see ACUSON-24-YBR_FULL-RLE.dcm )
611 zero == 0x0001 || zero == 0x0100 || zero == 0x0002 || zero == 0x0200 ||
612 zero == 0x0003 || zero == 0x0300 || zero == 0x0004 || zero == 0x0400 ||
613 zero == 0x0005 || zero == 0x0500 || zero == 0x0006 || zero == 0x0600 ||
614 zero == 0x0007 || zero == 0x0700 || zero == 0x0008 || zero == 0x0800 )
616 std::string msg = Util::Format(
617 "ACR/DICOM starting by 0x(%04x) at the beginning of the file\n", zero);
618 // FIXME : is it a Warning message, or a Debug message?
619 gdcmWarningMacro( msg.c_str() );
624 Fp->seekg(126L, std::ios::cur);
625 char dicm[4]; // = {' ',' ',' ',' '};
626 Fp->read(dicm, (size_t)4);
632 if ( memcmp(dicm, "DICM", 4) == 0 )
634 HasDCMPreamble = true;
638 // -- Neither ACR/No Preamble Dicom nor DICOMV3 file
640 // Don't user Warning nor Error, not to polute the output
641 // while directory recursive parsing ...
642 gdcmDebugMacro( "Neither ACR/No Preamble Dicom nor DICOMV3 file: "
643 << Filename.c_str());
648 * \brief closes the file
649 * @return TRUE if the close was successfull
651 bool Document::CloseFile()
663 * \brief Writes in a file all the Entries (Dicom Elements)
664 * @param fp file pointer on an already open file (actually: Output File Stream)
665 * @param filetype Type of the File to be written
666 * (ACR-NEMA, ExplicitVR, ImplicitVR)
668 void Document::WriteContent(std::ofstream *fp, FileType filetype)
670 // Skip if user wants to write an ACR-NEMA file
672 if ( filetype == ImplicitVR || filetype == ExplicitVR ||
675 // writing Dicom File Preamble
676 char filePreamble[128];
677 memset(filePreamble, 0, 128);
678 fp->write(filePreamble, 128);
679 fp->write("DICM", 4);
683 * \todo rewrite later, if really usefull
684 * - 'Group Length' element is optional in DICOM
685 * - but un-updated odd groups lengthes can causes pb
688 * if ( (filetype == ImplicitVR) || (filetype == ExplicitVR) )
689 * UpdateGroupLength(false,filetype);
690 * if ( filetype == ACR)
691 * UpdateGroupLength(true,ACR);
693 * --> Computing group length for groups with embeded Sequences
694 * --> was too much tricky / we were [in a hurry / too lazy]
695 * --> We don't write the element 0x0000 (group length)
698 ElementSet::WriteContent(fp, filetype); // This one is recursive
701 // -----------------------------------------
704 * \brief Loads (from disk) the element content
705 * when a string is not suitable
706 * @param group group number of the Entry
707 * @param elem element number of the Entry
709 void Document::LoadEntryBinArea(uint16_t group, uint16_t elem)
711 // Search the corresponding DocEntry
712 DocEntry *docEntry = GetDocEntry(group, elem);
715 gdcmDebugMacro(std::hex << group << "|" << elem
716 << " doesn't exist" );
719 DataEntry *dataEntry = dynamic_cast<DataEntry *>(docEntry);
722 gdcmWarningMacro(std::hex << group << "|" << elem
723 << " is NOT a DataEntry");
726 LoadEntryBinArea(dataEntry);
730 * \brief Loads (from disk) the element content
731 * when a string is not suitable
732 * @param entry Entry whose binArea is going to be loaded
734 void Document::LoadEntryBinArea(DataEntry *entry)
736 if( entry->GetBinArea() )
743 size_t o =(size_t)entry->GetOffset();
744 Fp->seekg(o, std::ios::beg);
746 size_t l = entry->GetLength();
747 uint8_t *data = new uint8_t[l];
750 gdcmWarningMacro( "Cannot allocate DataEntry content for : "
751 << std::hex << entry->GetGroup()
752 << "|" << entry->GetElement() );
757 Fp->read((char*)data, l);
758 if ( Fp->fail() || Fp->eof() )
761 entry->SetState(DataEntry::STATE_UNREAD);
765 // Swap the data content if necessary
767 unsigned short vrLgth =
768 Global::GetVR()->GetAtomicElementLength(entry->GetVR());
770 // FIXME : trouble expected if we read an ... OW Entry (LUT, etc ..)
771 // if( entry->GetVR() == "OW" )
782 uint16_t *data16 = (uint16_t *)data;
783 for(i=0;i<l/vrLgth;i++)
784 data16[i] = SwapShort(data16[i]);
789 uint32_t *data32 = (uint32_t *)data;
790 for(i=0;i<l/vrLgth;i++)
791 data32[i] = SwapLong(data32[i]);
796 double *data64 = (double *)data;
797 for(i=0;i<l/vrLgth;i++)
798 data64[i] = SwapDouble(data64[i]);
803 entry->SetBinArea(data);
810 * \brief Loads the element while preserving the current
811 * underlying file position indicator as opposed to
812 * LoadDocEntry that modifies it.
813 * @param entry DocEntry whose value will be loaded.
815 void Document::LoadDocEntrySafe(DocEntry *entry)
819 long PositionOnEntry = Fp->tellg();
821 Fp->seekg(PositionOnEntry, std::ios::beg);
826 * \brief Compares two documents, according to \ref DicomDir rules
827 * \warning Does NOT work with ACR-NEMA files
828 * \todo Find a trick to solve the pb (use RET fields ?)
829 * @param document to compare with current one
830 * @return true if 'smaller'
832 bool Document::operator<(Document &document)
835 std::string s1 = GetEntryString(0x0010,0x0010);
836 std::string s2 = document.GetEntryString(0x0010,0x0010);
848 s1 = GetEntryString(0x0010,0x0020);
849 s2 = document.GetEntryString(0x0010,0x0020);
860 // Study Instance UID
861 s1 = GetEntryString(0x0020,0x000d);
862 s2 = document.GetEntryString(0x0020,0x000d);
873 // Serie Instance UID
874 s1 = GetEntryString(0x0020,0x000e);
875 s2 = document.GetEntryString(0x0020,0x000e);
890 //-----------------------------------------------------------------------------
893 * \brief Reads a supposed to be 16 Bits integer
894 * (swaps it depending on processor endianness)
897 uint16_t Document::ReadInt16()
901 Fp->read ((char*)&g, (size_t)2);
904 throw FormatError( "Document::ReadInt16()", " file error." );
908 throw FormatError( "Document::ReadInt16()", "EOF." );
915 * \brief Reads a supposed to be 32 Bits integer
916 * (swaps it depending on processor endianness)
919 uint32_t Document::ReadInt32()
923 Fp->read ((char*)&g, (size_t)4);
926 throw FormatError( "Document::ReadInt32()", " file error." );
930 throw FormatError( "Document::ReadInt32()", "EOF." );
937 * \brief skips bytes inside the source file
940 void Document::SkipBytes(uint32_t nBytes)
942 //FIXME don't dump the returned value
943 Fp->seekg((long)nBytes, std::ios::cur);
947 * \brief Re-computes the length of the Dicom group 0002.
949 int Document::ComputeGroup0002Length( )
955 bool found0002 = false;
957 // for each zero-level Tag in the DCM Header
958 DocEntry *entry = GetFirstEntry();
961 gr = entry->GetGroup();
967 if ( entry->GetElement() != 0x0000 )
971 //if ( (vr == "OB")||(vr == "OW")||(vr == "UT")||(vr == "SQ"))
972 // (no SQ, OW, UT in group 0x0002;)
975 // explicit VR AND (OB, OW, SQ, UT) : 4 more bytes
979 groupLength += 2 + 2 + 4 + entry->GetLength();
985 entry = GetNextEntry();
991 * \brief CallStartMethod
993 void Document::CallStartMethod()
997 CommandManager::ExecuteCommand(this,CMD_STARTPROGRESS);
1001 * \brief CallProgressMethod
1003 void Document::CallProgressMethod()
1005 CommandManager::ExecuteCommand(this,CMD_PROGRESS);
1009 * \brief CallEndMethod
1011 void Document::CallEndMethod()
1014 CommandManager::ExecuteCommand(this,CMD_ENDPROGRESS);
1017 //-----------------------------------------------------------------------------
1020 * \brief Loads all the needed Dictionaries
1022 void Document::Initialize()
1024 RefPubDict = Global::GetDicts()->GetDefaultPubDict();
1030 * \brief Parses a DocEntrySet (Zero-level DocEntries or SQ Item DocEntries)
1031 * @param set DocEntrySet we are going to parse ('zero level' or a SQItem)
1032 * @param offset start of parsing
1033 * @param l_max length to parse (meaningless when we are in 'delimitor mode')
1034 * @param delim_mode : whether we are in 'delimitor mode' (l=0xffffff) or not
1036 void Document::ParseDES(DocEntrySet *set, long offset,
1037 long l_max, bool delim_mode)
1039 DocEntry *newDocEntry;
1040 DataEntry *newDataEntry;
1041 SeqEntry *newSeqEntry;
1043 bool used; // will be set to false when something wrong happens to an Entry.
1044 // (Entry will then be deleted)
1045 bool delim_mode_intern = delim_mode;
1047 gdcmDebugMacro( "Enter in ParseDES, delim-mode " << delim_mode
1048 << " at offset " << std::hex << "0x(" << offset << ")" );
1051 if ( !delim_mode && ((long)(Fp->tellg())-offset) >= l_max)
1056 newDocEntry = ReadNextDocEntry( );
1058 // Uncoment this cerr line to be able to 'follow' the DocEntries
1059 // when something *very* strange happens
1060 if( Debug::GetDebugFlag() )
1061 std::cerr<<newDocEntry->GetKey()<<" "<<newDocEntry->GetVR()<<std::endl;
1068 // an Item Starter found elsewhere but the first position
1069 // of a SeqEntry means previous entry was a Sequence
1070 // but we didn't get it (private Sequence + Implicit VR)
1071 // we have to backtrack.
1072 if ( !first && newDocEntry->IsItemStarter() )
1074 // Debug message within the method !
1075 newDocEntry = Backtrack(newDocEntry);
1079 PreviousDocEntry = newDocEntry;
1083 newDataEntry = dynamic_cast<DataEntry*>(newDocEntry);
1087 //////////////////////////// DataEntry
1089 vr = newDocEntry->GetVR();
1091 if ( !set->AddEntry( newDataEntry ) )
1093 gdcmDebugMacro( "in ParseDES : cannot add a DataEntry "
1094 << newDataEntry->GetKey()
1095 << " (at offset : 0x("
1096 << newDataEntry->GetOffset() << ") )" );
1101 newDataEntry->Delete();
1102 // Load only if we can add (not a duplicate key)
1103 LoadDocEntry( newDataEntry );
1105 if ( newDataEntry->GetElement() == 0x0000 ) // if on group length
1107 if ( newDataEntry->GetGroup()%2 != 0 ) // if Shadow Group
1109 if ( LoadMode & LD_NOSHADOW ) // if user asked to skip shad.gr
1111 std::string strLgrGroup = newDataEntry->GetString();
1114 //if ( newDataEntry->IsUnfound() ) /?!? JPR
1116 lgrGroup = atoi(strLgrGroup.c_str());
1117 Fp->seekg(lgrGroup, std::ios::cur);
1118 //used = false; // never used
1119 RemoveEntry( newDocEntry ); // Remove and delete
1120 // bcc 5.5 is right "assigned a value that's never used"
1128 bool delimitor = newDataEntry->IsItemDelimitor();
1131 (!delim_mode && ((long)(Fp->tellg())-offset) >= l_max) )
1134 newDocEntry->Delete();
1138 // Just to make sure we are at the beginning of next entry.
1139 SkipToNextDocEntry(newDocEntry);
1143 /////////////////////// SeqEntry : VR = "SQ"
1145 unsigned long l = newDocEntry->GetReadLength();
1146 if ( l != 0 ) // don't mess the delim_mode for 'zero-length sequence'
1148 if ( l == 0xffffffff )
1150 delim_mode_intern = true;
1154 delim_mode_intern = false;
1158 if ( (LoadMode & LD_NOSHADOWSEQ) && ! delim_mode_intern )
1160 // User asked to skip SeQuences *only* if they belong to Shadow Group
1161 if ( newDocEntry->GetGroup()%2 != 0 )
1163 Fp->seekg( l, std::ios::cur);
1164 newDocEntry->Delete(); // Delete, not in the set
1168 if ( (LoadMode & LD_NOSEQ) && ! delim_mode_intern )
1170 // User asked to skip *any* SeQuence
1171 Fp->seekg( l, std::ios::cur);
1172 newDocEntry->Delete(); // Delete, not in the set
1175 // delay the dynamic cast as late as possible
1176 newSeqEntry = dynamic_cast<SeqEntry*>(newDocEntry);
1178 // no other way to create the Delimitor ...
1179 newSeqEntry->SetDelimitorMode( delim_mode_intern );
1181 // At the top of the hierarchy, stands a Document. When "set"
1182 // is a Document, then we are building the first depth level.
1183 // Hence the SeqEntry we are building simply has a depth
1185 if ( set == this ) // ( dynamic_cast< Document* > ( set ) )
1187 newSeqEntry->SetDepthLevel( 1 );
1189 // But when "set" is already a SQItem, we are building a nested
1190 // sequence, and hence the depth level of the new SeqEntry
1191 // we are building, is one level deeper:
1193 // time waste hunting
1194 else if (SQItem *parentSQItem = dynamic_cast< SQItem* > ( set ) )
1196 newSeqEntry->SetDepthLevel( parentSQItem->GetDepthLevel() + 1 );
1200 { // Don't try to parse zero-length sequences
1202 gdcmDebugMacro( "Entry in ParseSQ, delim " << delim_mode_intern
1203 << " at offset 0x(" << std::hex
1204 << newDocEntry->GetOffset() << ")");
1206 ParseSQ( newSeqEntry,
1207 newDocEntry->GetOffset(),
1208 l, delim_mode_intern);
1210 gdcmDebugMacro( "Exit from ParseSQ, delim " << delim_mode_intern);
1213 if ( !set->AddEntry( newSeqEntry ) )
1215 gdcmWarningMacro( "in ParseDES : cannot add a SeqEntry "
1216 << newSeqEntry->GetKey()
1217 << " (at offset : 0x("
1218 << newSeqEntry->GetOffset() << ") )" );
1223 newDocEntry->Delete();
1226 if ( !delim_mode && ((long)(Fp->tellg())-offset) >= l_max)
1229 newDocEntry->Delete();
1232 } // end SeqEntry : VR = "SQ"
1236 newDocEntry->Delete();
1240 gdcmDebugMacro( "Exit from ParseDES, delim-mode " << delim_mode );
1244 * \brief Parses a Sequence ( SeqEntry after SeqEntry)
1245 * @return parsed length for this level
1247 void Document::ParseSQ( SeqEntry *seqEntry,
1248 long offset, long l_max, bool delim_mode)
1250 int SQItemNumber = 0;
1252 long offsetStartCurrentSQItem = offset;
1256 // the first time, we read the fff0,e000 of the first SQItem
1257 DocEntry *newDocEntry = ReadNextDocEntry();
1261 gdcmWarningMacro("in ParseSQ : should never get here!");
1266 if ( newDocEntry->IsSequenceDelimitor() )
1268 seqEntry->SetDelimitationItem( newDocEntry );
1269 newDocEntry->Delete();
1273 if ( !delim_mode && ((long)(Fp->tellg())-offset) >= l_max)
1275 newDocEntry->Delete();
1278 // create the current SQItem
1279 SQItem *itemSQ = SQItem::New( seqEntry->GetDepthLevel() );
1280 unsigned int l = newDocEntry->GetReadLength();
1282 if ( l == 0xffffffff )
1291 // remove fff0,e000, created out of the SQItem
1292 Fp->seekg(offsetStartCurrentSQItem, std::ios::beg);
1293 // fill up the current SQItem, starting at the beginning of fff0,e000
1295 ParseDES(itemSQ, offsetStartCurrentSQItem, l+8, dlm_mod);
1297 offsetStartCurrentSQItem = Fp->tellg();
1299 seqEntry->AddSQItem( itemSQ, SQItemNumber );
1301 newDocEntry->Delete();
1303 if ( !delim_mode && ((long)(Fp->tellg())-offset ) >= l_max )
1311 * \brief When a private Sequence + Implicit VR is encountered
1312 * we cannot guess it's a Sequence till we find the first
1313 * Item Starter. We then backtrack to do the job.
1314 * @param docEntry Item Starter that warned us
1316 DocEntry *Document::Backtrack(DocEntry *docEntry)
1318 // delete the Item Starter, built erroneously out of any Sequence
1319 // it's not yet in the HTable/chained list
1322 // Get all info we can from PreviousDocEntry
1323 uint16_t group = PreviousDocEntry->GetGroup();
1324 uint16_t elem = PreviousDocEntry->GetElement();
1325 uint32_t lgt = PreviousDocEntry->GetLength();
1326 long offset = PreviousDocEntry->GetOffset();
1328 gdcmDebugMacro( "Backtrack :" << std::hex << group
1330 << " at offset 0x(" <<offset << ")" );
1331 RemoveEntry( PreviousDocEntry );
1333 // forge the Seq Entry
1334 DocEntry *newEntry = NewSeqEntry(group, elem);
1335 newEntry->SetLength(lgt);
1336 newEntry->SetOffset(offset);
1338 // Move back to the beginning of the Sequence
1339 Fp->seekg( 0, std::ios::beg);
1340 Fp->seekg(offset, std::ios::cur);
1346 * \brief Loads (or not) the element content depending if its length exceeds
1347 * or not the value specified with Document::SetMaxSizeLoadEntry()
1348 * @param entry Header Entry (Dicom Element) to be dealt with
1349 * @param forceLoad whether you want to force loading of 'long' elements
1351 void Document::LoadDocEntry(DocEntry *entry, bool forceLoad)
1353 uint16_t group = entry->GetGroup();
1354 uint16_t elem = entry->GetElement();
1355 const VRKey &vr = entry->GetVR();
1356 uint32_t length = entry->GetLength();
1358 Fp->seekg((long)entry->GetOffset(), std::ios::beg);
1360 // A SeQuence "contains" a set of Elements.
1361 // (fffe e000) tells us an Element is beginning
1362 // (fffe e00d) tells us an Element just ended
1363 // (fffe e0dd) tells us the current SeQuence just ended
1365 // (fffe 0000) is an 'impossible' tag value,
1366 // found in MR-PHILIPS-16-Multi-Seq.dcm
1368 if ( (group == 0xfffe && elem != 0x0000 ) || vr == "SQ" )
1370 // NO more value field for SQ !
1374 DataEntry *dataEntryPtr = dynamic_cast< DataEntry* >(entry);
1380 // When the length is zero things are easy:
1383 dataEntryPtr->SetBinArea(NULL,true);
1387 // The elements whose length is bigger than the specified upper bound
1390 std::ostringstream s;
1394 if (length > MaxSizeLoadEntry)
1396 dataEntryPtr->SetBinArea(NULL,true);
1397 dataEntryPtr->SetState(DataEntry::STATE_NOTLOADED);
1399 // to be sure we are at the end of the value ...
1400 Fp->seekg((long)entry->GetOffset()+(long)entry->GetLength(),
1406 LoadEntryBinArea(dataEntryPtr); // last one, not to erase length !
1410 * \brief Find the value Length of the passed Doc Entry
1411 * @param entry Header Entry whose length of the value shall be loaded.
1413 void Document::FindDocEntryLength( DocEntry *entry )
1414 throw ( FormatError )
1416 const VRKey &vr = entry->GetVR();
1419 if ( Filetype == ExplicitVR && !entry->IsImplicitVR() )
1421 if ( vr == "OB" || vr == "OW" || vr == "SQ" || vr == "UT"
1424 // The following reserved two bytes (see PS 3.5-2003, section
1425 // "7.1.2 Data element structure with explicit vr", p 27) must be
1426 // skipped before proceeding on reading the length on 4 bytes.
1427 Fp->seekg( 2L, std::ios::cur);
1428 uint32_t length32 = ReadInt32();
1430 if ( (vr == "OB" || vr == "OW") && length32 == 0xffffffff )
1435 lengthOB = FindDocEntryLengthOBOrOW();
1437 catch ( FormatUnexpected )
1439 // Computing the length failed (this happens with broken
1440 // files like gdcm-JPEG-LossLess3a.dcm). We still have a
1441 // chance to get the pixels by deciding the element goes
1442 // until the end of the file. Hence we artificially fix the
1443 // the length and proceed.
1444 gdcmWarningMacro( " Computing the length failed for " <<
1445 entry->GetKey() <<" in " <<GetFileName());
1447 long currentPosition = Fp->tellg();
1448 Fp->seekg(0L,std::ios::end);
1450 long lengthUntilEOF = (long)(Fp->tellg())-currentPosition;
1451 Fp->seekg(currentPosition, std::ios::beg);
1453 entry->SetReadLength(lengthUntilEOF);
1454 entry->SetLength(lengthUntilEOF);
1457 entry->SetReadLength(lengthOB);
1458 entry->SetLength(lengthOB);
1461 FixDocEntryFoundLength(entry, length32);
1465 // Length is encoded on 2 bytes.
1466 length16 = ReadInt16();
1468 // 0xffff means that we deal with 'No Length' Sequence
1469 // or 'No Length' SQItem
1470 if ( length16 == 0xffff)
1474 FixDocEntryFoundLength( entry, (uint32_t)length16 );
1479 // Either implicit VR or a non DICOM conformal (see note below) explicit
1480 // VR that ommited the VR of (at least) this element. Farts happen.
1481 // [Note: according to the part 5, PS 3.5-2001, section 7.1 p25
1482 // on Data elements "Implicit and Explicit VR Data Elements shall
1483 // not coexist in a Data Set and Data Sets nested within it".]
1484 // Length is on 4 bytes.
1486 // Well ... group 0002 is always coded in 'Explicit VR Litle Endian'
1487 // even if Transfer Syntax is 'Implicit VR ...'
1488 // --> Except for 'Implicit VR Big Endian Transfer Syntax GE Private'
1490 FixDocEntryFoundLength( entry, ReadInt32() );
1496 * \brief Find the Length till the next sequence delimiter
1499 uint32_t Document::FindDocEntryLengthOBOrOW()
1500 throw( FormatUnexpected )
1502 // See PS 3.5-2001, section A.4 p. 49 on encapsulation of encoded pixel data.
1503 long positionOnEntry = Fp->tellg();
1504 bool foundSequenceDelimiter = false;
1505 uint32_t totalLength = 0;
1507 while ( !foundSequenceDelimiter )
1513 group = ReadInt16();
1516 catch ( FormatError )
1518 throw FormatError("Unexpected end of file encountered during ",
1519 "Document::FindDocEntryLengthOBOrOW()");
1521 // We have to decount the group and element we just read
1523 if ( group != 0xfffe || ( ( elem != 0xe0dd ) && ( elem != 0xe000 ) ) )
1525 long filePosition = Fp->tellg();
1527 "Neither an Item tag nor a Sequence delimiter tag on :"
1528 << std::hex << group << " , " << elem
1529 << ") -before- position x(" << filePosition << ")" );
1531 Fp->seekg(positionOnEntry, std::ios::beg);
1532 throw FormatUnexpected(
1533 "Neither an Item tag nor a Sequence delimiter tag.");
1535 if ( elem == 0xe0dd )
1537 foundSequenceDelimiter = true;
1539 uint32_t itemLength = ReadInt32();
1540 // We add 4 bytes since we just read the ItemLength with ReadInt32
1541 totalLength += itemLength + 4;
1542 SkipBytes(itemLength);
1544 if ( foundSequenceDelimiter )
1549 Fp->seekg( positionOnEntry, std::ios::beg);
1554 * \brief Find the Value Representation of the current Dicom Element.
1555 * @return Value Representation of the current Entry
1557 VRKey Document::FindDocEntryVR()
1559 if ( Filetype != ExplicitVR )
1560 return GDCM_VRUNKNOWN;
1562 long positionOnEntry = Fp->tellg();
1563 // Warning: we believe this is explicit VR (Value Representation) because
1564 // we used a heuristic that found "UL" in the first tag and/or
1565 // 'Transfer Syntax' told us it is.
1566 // Alas this doesn't guarantee that all the tags will be in explicit VR.
1567 // In some cases one finds implicit VR tags mixed within an explicit VR file.
1568 // Hence we make sure the present tag is in explicit VR and try to fix things
1569 // if it happens not to be the case.
1572 Fp->read(&(vr[0]),(size_t)2);
1574 if ( !CheckDocEntryVR(vr) )
1576 // Don't warn user with useless messages
1577 // Often, delimiters (0xfffe), are not explicit VR ...
1578 if ( CurrentGroup != 0xfffe )
1579 gdcmWarningMacro( "Unknown VR " << std::hex << "0x("
1580 << (unsigned int)vr[0] << "|" << (unsigned int)vr[1]
1581 << ") at offset : 0x(" << positionOnEntry<< ")" );
1582 Fp->seekg(positionOnEntry, std::ios::beg);
1583 return GDCM_VRUNKNOWN;
1589 * \brief Check the correspondance between the VR of the header entry
1590 * and the taken VR. If they are different, the header entry is
1591 * updated with the new VR.
1592 * @param vr Dicom Value Representation
1593 * @return false if the VR is incorrect or if the VR isn't referenced
1594 * otherwise, it returns true
1596 bool Document::CheckDocEntryVR(const VRKey &vr)
1598 return Global::GetVR()->IsValidVR(vr);
1602 * \brief Skip a given Header Entry
1603 * @param entry entry to skip
1605 void Document::SkipDocEntry(DocEntry *entry)
1607 SkipBytes(entry->GetLength());
1611 * \brief Skips to the beginning of the next Header Entry
1612 * @param currentDocEntry entry to skip
1614 void Document::SkipToNextDocEntry(DocEntry *currentDocEntry)
1616 int l = currentDocEntry->GetReadLength();
1617 if ( l == -1 ) // length = 0xffff shouldn't appear here ...
1618 // ... but PMS imagers happen !
1620 Fp->seekg((long)(currentDocEntry->GetOffset()), std::ios::beg);
1621 if (currentDocEntry->GetGroup() != 0xfffe) // for fffe pb
1623 Fp->seekg( (long)(currentDocEntry->GetReadLength()),std::ios::cur);
1628 * \brief When the length of an element value is obviously wrong (because
1629 * the parser went Jabberwocky) one can hope improving things by
1630 * applying some heuristics.
1631 * @param entry entry to check
1632 * @param foundLength first assumption about length
1634 void Document::FixDocEntryFoundLength(DocEntry *entry,
1635 uint32_t foundLength)
1637 entry->SetReadLength( foundLength );// will be updated only if a bug is found
1638 if ( foundLength == 0xffffffff)
1643 uint16_t gr = entry->GetGroup();
1644 uint16_t elem = entry->GetElement();
1646 if ( foundLength % 2)
1648 gdcmWarningMacro( "Warning : Tag with uneven length " << foundLength
1649 << " in x(" << std::hex << gr << "," << elem <<")");
1652 //////// Fix for some naughty General Electric images.
1653 // Allthough not recent many such GE corrupted images are still present
1654 // on Creatis hard disks. Hence this fix shall remain when such images
1655 // are no longer in use (we are talking a few years, here)...
1656 // Note: XMedCon probably uses such a trick since it is able to read
1657 // those pesky GE images ...
1658 if ( foundLength == 13)
1660 // Only happens for this length !
1661 if ( gr != 0x0008 || ( elem != 0x0070 && elem != 0x0080 ) )
1664 entry->SetReadLength(10); // a bug is to be fixed !?
1668 //////// Fix for some brain-dead 'Leonardo' Siemens images.
1669 // Occurence of such images is quite low (unless one leaves close to a
1670 // 'Leonardo' source. Hence, one might consider commenting out the
1671 // following fix on efficiency reasons.
1672 else if ( gr == 0x0009 && ( elem == 0x1113 || elem == 0x1114 ) )
1675 entry->SetReadLength(4); // a bug is to be fixed !
1678 else if ( entry->GetVR() == "SQ" )
1680 foundLength = 0; // ReadLength is unchanged
1683 //////// We encountered a 'delimiter' element i.e. a tag of the form
1684 // "fffe|xxxx" which is just a marker. Delimiters length should not be
1685 // taken into account.
1686 else if ( gr == 0xfffe )
1688 // According to the norm, fffe|0000 shouldn't exist. BUT the Philips
1689 // image gdcmData/gdcm-MR-PHILIPS-16-Multi-Seq.dcm happens to
1690 // causes extra troubles...
1691 if ( entry->GetElement() != 0x0000 )
1697 foundLength=12; // to skip the mess that follows this bugged Tag !
1700 entry->SetLength(foundLength);
1704 * \brief Apply some heuristics to predict whether the considered
1705 * element value contains/represents an integer or not.
1706 * @param entry The element value on which to apply the predicate.
1707 * @return The result of the heuristical predicate.
1709 bool Document::IsDocEntryAnInteger(DocEntry *entry)
1711 uint16_t elem = entry->GetElement();
1712 uint16_t group = entry->GetGroup();
1713 const VRKey &vr = entry->GetVR();
1714 uint32_t length = entry->GetLength();
1716 // When we have some semantics on the element we just read, and if we
1717 // a priori know we are dealing with an integer, then we shall be
1718 // able to swap it's element value properly.
1719 if ( elem == 0 ) // This is the group length of the group
1727 // Although this should never happen, still some images have a
1728 // corrupted group length [e.g. have a glance at offset x(8336) of
1729 // gdcmData/gdcm-MR-PHILIPS-16-Multi-Seq.dcm.
1730 // Since for dicom compliant and well behaved headers, the present
1731 // test is useless (and might even look a bit paranoid), when we
1732 // encounter such an ill-formed image, we simply display a warning
1733 // message and proceed on parsing (while crossing fingers).
1734 long filePosition = Fp->tellg();
1735 gdcmWarningMacro( "Erroneous Group Length element length on : ("
1736 << std::hex << group << " , " << elem
1737 << ") -before- position x(" << filePosition << ")"
1738 << "lgt : " << length );
1742 if ( vr == "UL" || vr == "US" || vr == "SL" || vr == "SS" )
1750 * \brief Discover what the swap code is (among little endian, big endian,
1751 * bad little endian, bad big endian).
1753 * @return false when we are absolutely sure
1754 * it's neither ACR-NEMA nor DICOM
1755 * true when we hope ours assuptions are OK
1757 bool Document::CheckSwap()
1764 // First, compare HostByteOrder and NetworkByteOrder in order to
1765 // determine if we shall need to swap bytes (i.e. the Endian type).
1766 bool net2host = Util::IsCurrentProcessorBigEndian();
1768 // The easiest case is the one of a 'true' DICOM header, we just have
1769 // to look for the string "DICM" inside the file preamble.
1772 char *entCur = deb + 128;
1773 if ( memcmp(entCur, "DICM", (size_t)4) == 0 )
1775 gdcmDebugMacro( "Looks like DICOM Version3 (preamble + DCM)" );
1777 // Group 0002 should always be VR, and the first element 0000
1778 // Let's be carefull (so many wrong headers ...)
1779 // and determine the value representation (VR) :
1780 // Let's skip to the first element (0002,0000) and check there if we find
1781 // "UL" - or "OB" if the 1st one is (0002,0001) -,
1782 // in which case we (almost) know it is explicit VR.
1783 // WARNING: if it happens to be implicit VR then what we will read
1784 // is the length of the group. If this ascii representation of this
1785 // length happens to be "UL" then we shall believe it is explicit VR.
1786 // We need to skip :
1787 // * the 128 bytes of File Preamble (often padded with zeroes),
1788 // * the 4 bytes of "DICM" string,
1789 // * the 4 bytes of the first tag (0002, 0000),or (0002, 0001)
1790 // i.e. a total of 136 bytes.
1793 // group 0x0002 *is always* Explicit VR Sometimes ,
1794 // even if elem 0002,0010 (Transfer Syntax) tells us the file is
1795 // *Implicit* VR (see former 'gdcmData/icone.dcm')
1797 if ( memcmp(entCur, "UL", (size_t)2) == 0 ||
1798 memcmp(entCur, "OB", (size_t)2) == 0 ||
1799 memcmp(entCur, "UI", (size_t)2) == 0 ||
1800 memcmp(entCur, "CS", (size_t)2) == 0 ) // CS, to remove later
1801 // when Write DCM *adds*
1803 // Use Document::dicom_vr to test all the possibilities
1804 // instead of just checking for UL, OB and UI !? group 0000
1806 Filetype = ExplicitVR;
1807 gdcmDebugMacro( "Group 0002 : Explicit Value Representation");
1811 Filetype = ImplicitVR;
1812 gdcmWarningMacro( "Group 0002 :Not an explicit Value Representation;"
1813 << "Looks like a bugged Header!");
1819 gdcmDebugMacro( "HostByteOrder != NetworkByteOrder, SwapCode = 4321");
1824 gdcmDebugMacro( "HostByteOrder = NetworkByteOrder, SwapCode = 1234");
1827 // Position the file position indicator at first tag
1828 // (i.e. after the file preamble and the "DICM" string).
1830 Fp->seekg(0, std::ios::beg); // FIXME : Is it usefull?
1832 Fp->seekg ( 132L, std::ios::beg);
1834 } // ------------------------------- End of DicomV3 ----------------
1836 // Alas, this is not a DicomV3 file and whatever happens there is no file
1837 // preamble. We can reset the file position indicator to where the data
1838 // is (i.e. the beginning of the file).
1840 gdcmWarningMacro( "Not a Kosher DICOM Version3 file (no preamble)");
1842 Fp->seekg(0, std::ios::beg);
1844 // Let's check 'No Preamble Dicom File' :
1845 // Should start with group 0x0002
1846 // and be Explicit Value Representation
1848 s16 = *((uint16_t *)(deb));
1861 if ( SwapCode != 0 )
1863 if ( memcmp(entCur, "UL", (size_t)2) == 0 ||
1864 memcmp(entCur, "OB", (size_t)2) == 0 ||
1865 memcmp(entCur, "UI", (size_t)2) == 0 ||
1866 memcmp(entCur, "SH", (size_t)2) == 0 ||
1867 memcmp(entCur, "AE", (size_t)2) == 0 ||
1868 memcmp(entCur, "OB", (size_t)2) == 0 )
1870 Filetype = ExplicitVR;
1871 gdcmDebugMacro( "Group 0002 : Explicit Value Representation");
1875 // ------------------------------- End of 'No Preamble' DicomV3 -------------
1877 // Our next best chance would be to be considering a 'clean' ACR/NEMA file.
1878 // By clean we mean that the length of the first group is written down.
1879 // If this is the case and since the length of the first group HAS to be
1880 // four (bytes), then determining the proper swap code is straightforward.
1883 // We assume the array of char we are considering contains the binary
1884 // representation of a 32 bits integer. Hence the following dirty
1886 s32 = *((uint32_t *)(entCur));
1906 // We are out of luck. It is not a DicomV3 nor a 'clean' ACR/NEMA file.
1907 // It is time for despaired wild guesses.
1908 // So, let's check if this file wouldn't happen to be 'dirty' ACR/NEMA,
1909 // i.e. the 'group length' element is not present :
1911 // check the supposed-to-be 'group number'
1912 // in ( 0x0001 .. 0x0008 )
1913 // to determine ' SwapCode' value .
1914 // Only 0 or 4321 will be possible
1915 // (no oportunity to check for the formerly well known
1916 // ACR-NEMA 'Bad Big Endian' or 'Bad Little Endian'
1917 // if unsuccessfull (i.e. neither 0x0002 nor 0x0200 etc-3, 4, ..., 8-)
1918 // the file IS NOT ACR-NEMA nor DICOM V3
1919 // Find a trick to tell it the caller...
1921 s16 = *((uint16_t *)(deb));
1948 gdcmWarningMacro("ACR/NEMA unfound swap info (Hopeless !)");
1956 * \brief Change the Byte Swap code.
1958 void Document::SwitchByteSwapCode()
1960 gdcmDebugMacro( "Switching Byte Swap code from "<< SwapCode
1961 << " at: 0x" << std::hex << Fp->tellg() );
1962 if ( SwapCode == 1234 )
1966 else if ( SwapCode == 4321 )
1970 else if ( SwapCode == 3412 )
1974 else if ( SwapCode == 2143 )
1978 gdcmDebugMacro( " Into: "<< SwapCode );
1982 * \brief during parsing, Header Elements too long are not loaded in memory
1983 * @param newSize new size
1985 void Document::SetMaxSizeLoadEntry(long newSize)
1991 if ((uint32_t)newSize >= (uint32_t)0xffffffff )
1993 MaxSizeLoadEntry = 0xffffffff;
1996 MaxSizeLoadEntry = newSize;
2000 * \brief Read the next tag WITHOUT loading it's value
2001 * (read the 'Group Number', the 'Element Number',
2002 * gets the Dict Entry
2003 * gets the VR, gets the length, gets the offset value)
2004 * @return On succes : the newly created DocEntry, NULL on failure.
2006 DocEntry *Document::ReadNextDocEntry()
2010 CurrentGroup = ReadInt16();
2011 CurrentElem = ReadInt16();
2013 catch ( FormatError )
2015 // We reached the EOF (or an error occured) therefore
2016 // header parsing has to be considered as finished.
2020 // Sometimes file contains groups of tags with reversed endianess.
2021 HandleBrokenEndian(CurrentGroup, CurrentElem);
2023 // In 'true DICOM' files Group 0002 is always little endian
2024 if ( HasDCMPreamble )
2025 HandleOutOfGroup0002(CurrentGroup, CurrentElem);
2027 VRKey vr = FindDocEntryVR();
2031 if ( vr == GDCM_VRUNKNOWN )
2033 if ( CurrentElem == 0x0000 ) // Group Length
2035 realVR = "UL"; // must be UL
2037 else if (CurrentGroup%2 == 1 &&
2038 (CurrentElem >= 0x0010 && CurrentElem <=0x00ff ))
2040 // DICOM PS 3-5 7.8.1 a) states that those
2041 // (gggg-0010->00FF where gggg is odd) attributes have to be LO
2046 DictEntry *dictEntry = GetDictEntry(CurrentGroup,CurrentElem);
2049 realVR = dictEntry->GetVR();
2050 dictEntry->Unregister();
2054 // gdcmDebugMacro( "Found VR: " << vr << " / Real VR: " << realVR );
2057 if ( Global::GetVR()->IsVROfSequence(realVR) )
2058 newEntry = NewSeqEntry(CurrentGroup, CurrentElem);
2061 newEntry = NewDataEntry(CurrentGroup, CurrentElem, realVR);
2062 static_cast<DataEntry *>(newEntry)->SetState(DataEntry::STATE_NOTLOADED);
2065 if ( vr == GDCM_VRUNKNOWN )
2067 if ( Filetype == ExplicitVR )
2069 // We thought this was explicit VR, but we end up with an
2070 // implicit VR tag. Let's backtrack.
2071 if ( newEntry->GetGroup() != 0xfffe )
2074 int offset = Fp->tellg();
2076 "Entry (%04x,%04x) at x(%x) should be Explicit VR\n",
2077 newEntry->GetGroup(), newEntry->GetElement(), offset );
2078 gdcmWarningMacro( msg.c_str() );
2081 newEntry->SetImplicitVR();
2086 FindDocEntryLength(newEntry);
2088 catch ( FormatError )
2095 newEntry->SetOffset(Fp->tellg());
2101 * \brief Handle broken private tag from Philips NTSCAN
2102 * where the endianess is being switched to BigEndian
2103 * for no apparent reason
2106 void Document::HandleBrokenEndian(uint16_t &group, uint16_t &elem)
2108 // Endian reversion.
2109 // Some files contain groups of tags with reversed endianess.
2110 static int reversedEndian = 0;
2111 // try to fix endian switching in the middle of headers
2112 if ((group == 0xfeff) && (elem == 0x00e0))
2114 // start endian swap mark for group found
2115 gdcmDebugMacro( "Start endian swap mark found." );
2117 SwitchByteSwapCode();
2122 else if (group == 0xfffe && elem == 0xe00d && reversedEndian)
2124 // end of reversed endian group
2125 gdcmDebugMacro( "End of reversed endian." );
2127 SwitchByteSwapCode();
2129 else if (group == 0xfeff && elem == 0xdde0)
2131 // reversed Sequence Terminator found
2132 // probabely a bug in the header !
2133 // Do what you want, it breaks !
2135 //SwitchByteSwapCode();
2136 gdcmWarningMacro( "Should never get here! reversed Sequence Terminator!" );
2141 else if (group == 0xfffe && elem == 0xe0dd)
2143 gdcmDebugMacro( "Straight Sequence Terminator." );
2148 * \brief Group 0002 is always coded Little Endian
2149 * whatever Transfer Syntax is
2152 void Document::HandleOutOfGroup0002(uint16_t &group, uint16_t &elem)
2154 // Endian reversion.
2155 // Some files contain groups of tags with reversed endianess.
2156 if ( !Group0002Parsed && group != 0x0002)
2158 Group0002Parsed = true;
2159 // we just came out of group 0002
2160 // if Transfer Syntax is Big Endian we have to change CheckSwap
2162 std::string ts = GetTransferSyntax();
2164 // Group 0002 is always 'Explicit ...'
2165 // even when Transfer Syntax says 'Implicit ..."
2167 if ( Global::GetTS()->GetSpecialTransferSyntax(ts) ==
2168 TS::ImplicitVRLittleEndian )
2170 Filetype = ImplicitVR;
2173 // FIXME Strangely, this works with
2174 //'Implicit VR BigEndian Transfer Syntax' (GE Private)
2176 // --> Probabely normal, since we considered we never have
2177 // to trust manufacturers.
2178 // (we find very often 'Implicit VR' tag,
2179 // even when Transfer Syntax tells us it's Explicit ...
2180 if ( Global::GetTS()->GetSpecialTransferSyntax(ts) ==
2181 TS::ExplicitVRBigEndian )
2183 gdcmDebugMacro("Transfer Syntax Name = ["
2184 << GetTransferSyntaxName() << "]" );
2185 SwitchByteSwapCode();
2186 group = SwapShort(group);
2187 elem = SwapShort(elem);
2190 /// \todo find a trick to warn user and stop processing
2192 if ( Global::GetTS()->GetSpecialTransferSyntax(ts) ==
2193 TS::DeflatedExplicitVRLittleEndian)
2195 gdcmWarningMacro("Transfer Syntax ["
2196 << GetTransferSyntaxName() << "] :"
2197 << " not yet dealt with ");
2201 // The following shouldn't occur very often
2202 // Let's check at the very end.
2204 if ( ts == GDCM_UNKNOWN )
2206 gdcmDebugMacro("True DICOM File, with NO Transfer Syntax (?!) " );
2210 if ( !Global::GetTS()->IsTransferSyntax(ts) )
2212 gdcmWarningMacro("True DICOM File, with illegal Transfer Syntax: ["
2219 //-----------------------------------------------------------------------------
2222 //-----------------------------------------------------------------------------
2223 } // end namespace gdcm