-#define HEADER_LENGHT_TO_READ 256 // on ne lit plus que le debut
-
-namespace Error {
- struct FileReadError {
- FileReadError(FILE* fp, const char* Mesg) {
- if (feof(fp))
- dbg.Verbose(1, "EOF encountered :", Mesg);
- if (ferror(fp))
- dbg.Verbose(1, "Error on reading :", Mesg);
- }
- };
-}
-
-//FIXME: this looks dirty to me...
-#define str2num(str, typeNum) *((typeNum *)(str))
-
-VRHT * gdcmHeader::dicom_vr = (VRHT*)0;
-gdcmDictSet* gdcmHeader::Dicts = new gdcmDictSet();
-
-void gdcmHeader::Initialise(void) {
- if (!gdcmHeader::dicom_vr)
- InitVRDict();
- RefPubDict = gdcmHeader::Dicts->GetDefaultPublicDict();
- RefShaDict = (gdcmDict*)0;
-}
-
-gdcmHeader::gdcmHeader (const char* InFilename) {
- SetMaxSizeLoadElementValue(1024);
- filename = InFilename;
- Initialise();
- fp=fopen(InFilename,"rw");
- dbg.Error(!fp, "gdcmHeader::gdcmHeader cannot open file", InFilename);
- ParseHeader();
-}
-
-gdcmHeader::~gdcmHeader (void) {
- fclose(fp);
- return;
-}
-
-void gdcmHeader::InitVRDict (void) {
- if (dicom_vr) {
- dbg.Verbose(0, "gdcmHeader::InitVRDict:", "VR dictionary allready set");
- return;
- }
- VRHT *vr = new VRHT;
- (*vr)["AE"] = "Application Entity"; // At most 16 bytes
- (*vr)["AS"] = "Age String"; // Exactly 4 bytes
- (*vr)["AT"] = "Attribute Tag"; // 2 16-bit unsigned short integers
- (*vr)["CS"] = "Code String"; // At most 16 bytes
- (*vr)["DA"] = "Date"; // Exactly 8 bytes
- (*vr)["DS"] = "Decimal String"; // At most 16 bytes
- (*vr)["DT"] = "Date Time"; // At most 26 bytes
- (*vr)["FL"] = "Floating Point Single"; // 32-bit IEEE 754:1985 float
- (*vr)["FD"] = "Floating Point Double"; // 64-bit IEEE 754:1985 double
- (*vr)["IS"] = "Integer String"; // At most 12 bytes
- (*vr)["LO"] = "Long String"; // At most 64 chars
- (*vr)["LT"] = "Long Text"; // At most 10240 chars
- (*vr)["OB"] = "Other Byte String"; // String of bytes (vr independant)
- (*vr)["OW"] = "Other Word String"; // String of 16-bit words (vr dep)
- (*vr)["PN"] = "Person Name"; // At most 64 chars
- (*vr)["SH"] = "Short String"; // At most 16 chars
- (*vr)["SL"] = "Signed Long"; // Exactly 4 bytes
- (*vr)["SQ"] = "Sequence of Items"; // Not Applicable
- (*vr)["SS"] = "Signed Short"; // Exactly 2 bytes
- (*vr)["ST"] = "Short Text"; // At most 1024 chars
- (*vr)["TM"] = "Time"; // At most 16 bytes
- (*vr)["UI"] = "Unique Identifier"; // At most 64 bytes
- (*vr)["UL"] = "Unsigned Long "; // Exactly 4 bytes
- (*vr)["UN"] = "Unknown"; // Any length of bytes
- (*vr)["US"] = "Unsigned Short "; // Exactly 2 bytes
- (*vr)["UT"] = "Unlimited Text"; // At most 2^32 -1 chars
- dicom_vr = vr;
-}
-
-/**
- * \ingroup gdcmHeader
- * \brief La seule maniere sure que l'on aie pour determiner
- * si on est en LITTLE_ENDIAN, BIG-ENDIAN,
- * BAD-LITTLE-ENDIAN, BAD-BIG-ENDIAN
- * est de trouver l'element qui donne la longueur d'un 'GROUP'
- * (on sait que la longueur de cet element vaut 0x00000004)
- * et de regarder comment cette longueur est codee en memoire
- *
- * Le probleme vient de ce que parfois, il n'y en a pas ...
- *
- * On fait alors le pari qu'on a a faire a du LITTLE_ENDIAN propre.
- * (Ce qui est la norme -pas respectee- depuis ACR-NEMA)
- * Si ce n'est pas le cas, on ne peut rien faire.
- *
- * (il faudrait avoir des fonctions auxquelles
- * on passe le code Swap en parametre, pour faire des essais 'manuels')
- */
-void gdcmHeader::CheckSwap()
-{
- guint32 s;
- guint32 x=4; // x : pour ntohs
- bool net2host; // true when HostByteOrder is the same as NetworkByteOrder
-
- int lgrLue;
- char * entCur;
- char deb[HEADER_LENGHT_TO_READ];
-
- // First, compare HostByteOrder and NetworkByteOrder in order to
- // determine if we shall need to swap bytes (i.e. the Endian type).
- if (x==ntohs(x))
- net2host = true;
- else
- net2host = false;
-
- // The easiest case is the one of a DICOM header, since it possesses a
- // file preamble where it suffice to look for the sting "DICM".
- lgrLue = fread(deb, 1, HEADER_LENGHT_TO_READ, fp);
-
- entCur = deb + 128;
- if(memcmp(entCur, "DICM", (size_t)4) == 0) {
- filetype = TrueDicom;
- dbg.Verbose(1, "gdcmHeader::CheckSwap:", "looks like DICOM Version3");
- } else {
- filetype = Unknown;
- dbg.Verbose(1, "gdcmHeader::CheckSwap:", "not a DICOM Version3 file");
- }
-
- if(filetype == TrueDicom) {
- // Next, determine the value representation (VR). Let's skip to the
- // first element (0002, 0000) and check there if we find "UL", in
- // which case we (almost) know it is explicit VR.
- // WARNING: if it happens to be implicit VR then what we will read
- // is the length of the group. If this ascii representation of this
- // length happens to be "UL" then we shall believe it is explicit VR.
- // FIXME: in order to fix the above warning, we could read the next
- // element value (or a couple of elements values) in order to make
- // sure we are not commiting a big mistake.
- // We need to skip :
- // * the 128 bytes of File Preamble (often padded with zeroes),
- // * the 4 bytes of "DICM" string,
- // * the 4 bytes of the first tag (0002, 0000),
- // i.e. a total of 136 bytes.
- entCur = deb + 136;
- if(memcmp(entCur, "UL", (size_t)2) == 0) {
- filetype = ExplicitVR;
- dbg.Verbose(1, "gdcmHeader::CheckSwap:",
- "explicit Value Representation");
- } else {
- filetype = ImplicitVR;
- dbg.Verbose(1, "gdcmHeader::CheckSwap:",
- "not an explicit Value Representation");
- }
-
- if (net2host) {
- sw = 4321;
- dbg.Verbose(1, "gdcmHeader::CheckSwap:",
- "HostByteOrder != NetworkByteOrder");
- } else {
- sw = 0;
- dbg.Verbose(1, "gdcmHeader::CheckSwap:",
- "HostByteOrder = NetworkByteOrder");
- }
-
- // Position the file position indicator at first tag (i.e.
- // after the file preamble and the "DICM" string).
- rewind(fp);
- fseek (fp, 132L, SEEK_SET);
- return;
- } // End of TrueDicom
-
- // Alas, this is not a DicomV3 file and whatever happens there is no file
- // preamble. We can reset the file position indicator to where the data
- // is (i.e. the beginning of the file).
- rewind(fp);
-
- // Our next best chance would be to be considering a 'clean' ACR/NEMA file.
- // By clean we mean that the length of the first tag is written down.
- // If this is the case and since the length of the first group HAS to be
- // four (bytes), then determining the proper swap code is straightforward.
-
- entCur = deb + 4;
- s = str2num(entCur, guint32);
-
- switch (s) {
- case 0x00040000 :
- sw = 3412;
- filetype = ACR;
- return;
- case 0x04000000 :
- sw = 4321;
- filetype = ACR;
- return;
- case 0x00000400 :
- sw = 2143;
- filetype = ACR;
- return;
- case 0x00000004 :
- sw = 0;
- filetype = ACR;
- return;
- default :
- dbg.Verbose(0, "gdcmHeader::CheckSwap:",
- "ACE/NEMA unfound swap info (time to raise bets)");
- }
-
- // We are out of luck. It is not a DicomV3 nor a 'clean' ACR/NEMA file.
- // It is time for despaired wild guesses. So, let's assume this file
- // happens to be 'dirty' ACR/NEMA, i.e. the length of the group is
- // not present. Then the only info we have is the net2host one.
- //FIXME Si c'est du RAW, ca degagera + tard
-
- if (! net2host )
- sw = 0;
- else
- sw = 4321;
- return;
-}
-
-void gdcmHeader::SwitchSwapToBigEndian(void) {
- dbg.Verbose(1, "gdcmHeader::SwitchSwapToBigEndian",
- "Switching to BigEndian mode.");
- if ( sw == 0 ) {
- sw = 4321;
- return;
- }
- if ( sw == 4321 ) {
- sw = 0;
- return;
- }
- if ( sw == 3412 ) {
- sw = 2143;
- return;
- }
- if ( sw == 2143 )
- sw = 3412;
-}
-
-/**
- * \ingroup gdcmHeader
- * \brief recupere la longueur d'un champ DICOM.
- * Preconditions:
- * 1/ le fichier doit deja avoir ete ouvert,
- * 2/ CheckSwap() doit avoir ete appele
- * 3/ la partie 'group' ainsi que la partie 'elem'
- * de l'acr_element doivent avoir ete lues.
- *
- * ACR-NEMA : we allways get
- * GroupNumber (2 Octets)
- * ElementNumber (2 Octets)
- * ElementSize (4 Octets)
- * DICOM en implicit Value Representation :
- * GroupNumber (2 Octets)
- * ElementNumber (2 Octets)
- * ElementSize (4 Octets)
- *
- * DICOM en explicit Value Representation :
- * GroupNumber (2 Octets)
- * ElementNumber (2 Octets)
- * ValueRepresentation (2 Octets)
- * ElementSize (2 Octets)
- *
- * ATTENTION : dans le cas ou ValueRepresentation = OB, OW, SQ, UN
- * GroupNumber (2 Octets)
- * ElementNumber (2 Octets)
- * ValueRepresentation (2 Octets)
- * zone reservee (2 Octets)
- * ElementSize (4 Octets)
- *
- * @param sw code swap
- * @param skippedLength pointeur sur nombre d'octets que l'on a saute qd
- * la lecture est finie
- * @param longueurLue pointeur sur longueur (en nombre d'octets)
- * effectivement lue
- * @return longueur retenue pour le champ
- */
-
-void gdcmHeader::FindVR( ElValue *ElVal) {
- if (filetype != ExplicitVR)
- return;
-
- char VR[3];
- string vr;
- int lgrLue;
- long PositionOnEntry = ftell(fp);
- // Warning: we believe this is explicit VR (Value Representation) because
- // we used a heuristic that found "UL" in the first tag. Alas this
- // doesn't guarantee that all the tags will be in explicit VR. In some
- // cases (see e-film filtered files) one finds implicit VR tags mixed
- // within an explicit VR file. Hence we make sure the present tag
- // is in explicit VR and try to fix things if it happens not to be
- // the case.
- bool RealExplicit = true;
-
- lgrLue=fread (&VR, (size_t)2,(size_t)1, fp);
- VR[2]=0;
- vr = string(VR);
-
- // Assume we are reading a falsely explicit VR file i.e. we reached
- // a tag where we expect reading a VR but are in fact we read the
- // first to bytes of the length. Then we will interogate (through find)
- // the dicom_vr dictionary with oddities like "\004\0" which crashes
- // both GCC and VC++ implentations of the STL map. Hence when the
- // expected VR read happens to be non-ascii characters we consider
- // we hit falsely explicit VR tag.
-
- if ( (!isalpha(VR[0])) && (!isalpha(VR[1])) )
- RealExplicit = false;
-
- // CLEANME searching the dicom_vr at each occurence is expensive.
- // PostPone this test in an optional integrity check at the end
- // of parsing or only in debug mode.
- if ( RealExplicit && !dicom_vr->count(vr) )
- RealExplicit = false;
-
- if ( RealExplicit ) {
- if ( ElVal->IsVrUnknown() ) {
- // When not a dictionary entry, we can safely overwrite the vr.
- ElVal->SetVR(vr);
- return;
- }
- if ( ElVal->GetVR() == vr ) {
- // The vr we just read and the dictionary agree. Nothing to do.
- return;
- }
- // The vr present in the file and the dictionary disagree. We assume
- // the file writer knew best and use the vr of the file. Since it would
- // be unwise to overwrite the vr of a dictionary (since it would
- // compromise it's next user), we need to clone the actual DictEntry
- // and change the vr for the read one.
- gdcmDictEntry* NewTag = new gdcmDictEntry(ElVal->GetGroup(),
- ElVal->GetElement(),
- vr,
- "FIXME",
- ElVal->GetName());
- ElVal->SetDictEntry(NewTag);
- return;
- }
-
- // We thought this was explicit VR, but we end up with an
- // implicit VR tag. Let's backtrack.
- dbg.Verbose(1, "gdcmHeader::FindVR:", "Falsely explicit vr file");
- fseek(fp, PositionOnEntry, SEEK_SET);
- // When this element is known in the dictionary we shall use, e.g. for
- // the semantics (see the usage of IsAnInteger), the vr proposed by the
- // dictionary entry. Still we have to flag the element as implicit since
- // we know now our assumption on expliciteness is not furfilled.
- // avoid .
- if ( ElVal->IsVrUnknown() )
- ElVal->SetVR("Implicit");
- ElVal->SetImplicitVr();
-}
-
-/**
- * \ingroup gdcmHeader
- * \brief Determines if the Transfer Syntax was allready encountered
- * and if it corresponds to a Big Endian one.
- *
- * @return True when big endian found. False in all other cases.
- */
-bool gdcmHeader::IsBigEndianTransferSyntax(void) {
- ElValue* Element = PubElVals.GetElement(0x0002, 0x0010);
- if ( !Element )
- return false;
- LoadElementValueSafe(Element);
- string Transfer = Element->GetValue();
- if ( Transfer == "1.2.840.10008.1.2.2" )
- return true;
- return false;
-}
-
-void gdcmHeader::FixFoundLength(ElValue * ElVal, guint32 FoudLength) {
- // Heuristic: a final fix.
- if ( FoudLength == 0xffffffff)
- FoudLength = 0;
- ElVal->SetLength(FoudLength);
-}
-
-void gdcmHeader::FindLength( ElValue * ElVal) {
- guint16 element = ElVal->GetElement();
- string vr = ElVal->GetVR();
- guint16 length16;
-
- if ( (filetype == ExplicitVR) && ! ElVal->IsImplicitVr() ) {
-
- if ( (vr=="OB") || (vr=="OW") || (vr=="SQ") || (vr=="UN") ) {
- // The following reserved two bytes (see PS 3.5-2001, section
- // 7.1.2 Data element structure with explicit vr p27) must be
- // skipped before proceeding on reading the length on 4 bytes.
- fseek(fp, 2L, SEEK_CUR);
- FixFoundLength(ElVal, ReadInt32());
- return;
- }
-
- // Length is encoded on 2 bytes.
- length16 = ReadInt16();
-
- // We can tell the current file is encoded in big endian (like
- // Data/US-RGB-8-epicard) when we find the "Transfer Syntax" tag
- // and it's value is the one of the encoding of a bie endian file.
- // In order to deal with such big endian encoded files, we have
- // (at least) two strategies:
- // * when we load the "Transfer Syntax" tag with value of big endian
- // encoding, we raise the proper flags. Then we wait for the end
- // of the META group (0x0002) among which is "Transfer Syntax",
- // before switching the swap code to big endian. We have to postpone
- // the switching of the swap code since the META group is fully encoded
- // in little endian, and big endian coding only starts at the next
- // group. The corresponding code can be hard to analyse and adds
- // many additional unnecessary tests for regular tags.
- // * the second strategy consist to wait for trouble, that shall appear
- // when we find the first group with big endian encoding. This is
- // easy to detect since the length of a "Group Length" tag (the
- // ones with zero as element number) has to be of 4 (0x0004). When we
- // encouter 1024 (0x0400) chances are the encoding changed and we
- // found a group with big endian encoding.
- // We shall use this second strategy. In order make sure that we
- // can interpret the presence of an apparently big endian encoded
- // length of a "Group Length" without committing a big mistake, we
- // add an additional check: we look in the allready parsed elements
- // for the presence of a "Transfer Syntax" whose value has to be "big
- // endian encoding". When this is the case, chances are we got our
- // hands on a big endian encoded file: we switch the swap code to
- // big endian and proceed...
- if ( (element == 0) && (length16 == 1024) ) {
- if ( ! IsBigEndianTransferSyntax() )
- throw Error::FileReadError(fp, "gdcmHeader::FindLength");
- length16 = 4;
- SwitchSwapToBigEndian();
- // Restore the unproperly loaded values i.e. the group, the element
- // and the dictionary entry depending on them.
- guint16 CorrectGroup = SwapShort(ElVal->GetGroup());
- guint16 CorrectElem = SwapShort(ElVal->GetElement());
- gdcmDictEntry * NewTag = IsInDicts(CorrectGroup, CorrectElem);
- if (!NewTag) {
- // This correct tag is not in the dictionary. Create a new one.
- NewTag = new gdcmDictEntry(CorrectGroup, CorrectElem);
- }
- // FIXME this can create a memory leaks on the old entry that be
- // left unreferenced.
- ElVal->SetDictEntry(NewTag);
- }
-
- // Heuristic: well some files are really ill-formed.
- if ( length16 == 0xffff) {
- length16 = 0;
- dbg.Verbose(0, "gdcmHeader::FindLength",
- "Erroneous element length fixed.");
- }
- FixFoundLength(ElVal, (guint32)length16);
- return;
- }
-
- // Either implicit VR or a non DICOM conformal (see not below) explicit
- // VR that ommited the VR of (at least) this element. Farts happen.
- // [Note: according to the part 5, PS 3.5-2001, section 7.1 p25
- // on Data elements "Implicit and Explicit VR Data Elements shall
- // not coexist in a Data Set and Data Sets nested within it".]
- // Length is on 4 bytes.
- FixFoundLength(ElVal, ReadInt32());
-}
-
-/**
- * \ingroup gdcmHeader
- * \brief Swaps back the bytes of 4-byte long integer accordingly to
- * processor order.
- *
- * @return The suggested integer.
- */
-guint32 gdcmHeader::SwapLong(guint32 a) {
- // FIXME: il pourrait y avoir un pb pour les entiers negatifs ...
- switch (sw) {
- case 0 :
- break;
- case 4321 :
- a=( ((a<<24) & 0xff000000) | ((a<<8) & 0x00ff0000) |
- ((a>>8) & 0x0000ff00) | ((a>>24) & 0x000000ff) );
- break;
-
- case 3412 :
- a=( ((a<<16) & 0xffff0000) | ((a>>16) & 0x0000ffff) );
- break;
-
- case 2143 :
- a=( ((a<<8) & 0xff00ff00) | ((a>>8) & 0x00ff00ff) );
- break;
- default :
- dbg.Error(" gdcmHeader::SwapLong : unset swap code");
- a=0;
- }
- return(a);
-}
-
-/**
- * \ingroup gdcmHeader
- * \brief Swaps the bytes so they agree with the processor order
- * @return The properly swaped 16 bits integer.
- */
-guint16 gdcmHeader::SwapShort(guint16 a) {
- if ( (sw==4321) || (sw==2143) )
- a =(((a<<8) & 0x0ff00) | ((a>>8)&0x00ff));
- return (a);
-}
-
-void gdcmHeader::SkipElementValue(ElValue * ElVal) {
- //FIXME don't dump the returned value
- (void)fseek(fp, (long)ElVal->GetLength(), SEEK_CUR);
-}
-
-void gdcmHeader::SetMaxSizeLoadElementValue(long NewSize) {
- if (NewSize < 0)
- return;
- if ((guint32)NewSize >= (guint32)0xffffffff) {
- MaxSizeLoadElementValue = 0xffffffff;
- return;
- }
- MaxSizeLoadElementValue = NewSize;
-}
-
-/**
- * \ingroup gdcmHeader
- * \brief Loads the element if it's size is not to big.
- * @param ElVal Element whose value shall be loaded.
- * @param MaxSize Size treshold above which the element value is not
- * loaded in memory. The element value is allways loaded
- * when MaxSize is equal to UINT32_MAX.
- * @return
- */
-void gdcmHeader::LoadElementValue(ElValue * ElVal) {
- size_t item_read;
- guint16 group = ElVal->GetGroup();
- guint16 elem = ElVal->GetElement();
- string vr = ElVal->GetVR();
- guint32 length = ElVal->GetLength();
- bool SkipLoad = false;
-
- fseek(fp, (long)ElVal->GetOffset(), SEEK_SET);
-
- // Sequences not treated yet !
- if( vr == "SQ" )
- SkipLoad = true;
-
- // Heuristic : a sequence "contains" a set of tags (called items). It looks
- // like the last tag of a sequence (the one that terminates the sequence)
- // has a group of 0xfffe (with a dummy length).
- if( group == 0xfffe )
- SkipLoad = true;
-
- // The group length doesn't represent data to be loaded in memory, since
- // each element of the group shall be loaded individualy.
- if( elem == 0 )
- SkipLoad = true;
-
- if ( SkipLoad ) {
- // FIXME the following skip is not necessary
- SkipElementValue(ElVal);
- ElVal->SetLength(0);
- ElVal->SetValue("gdcm::Skipped");
- return;
- }
-
- // When the length is zero things are easy:
- if ( length == 0 ) {
- ElVal->SetValue("");
- return;
- }
-
- // Values bigger than specified are not loaded.
- if (length > MaxSizeLoadElementValue) {
- ostringstream s;
- s << "gdcm::NotLoaded.";
- s << " Address:" << (long)ElVal->GetOffset();
- s << " Length:" << ElVal->GetLength();
- //mesg += " Length:" + ElVal->GetLength();
- ElVal->SetValue(s.str());
- return;
- }
-
- // When an integer is expected, read and convert the following two or
- // four bytes properly i.e. as an integer as opposed to a string.
- if ( IsAnInteger(ElVal) ) {
- guint32 NewInt;
- if( length == 2 ) {
- NewInt = ReadInt16();
- } else if( length == 4 ) {
- NewInt = ReadInt32();
- } else
- dbg.Error(true, "LoadElementValue: Inconsistency when reading Int.");
-
- //FIXME: make the following an util fonction
- ostringstream s;
- s << NewInt;
- ElVal->SetValue(s.str());
- return;
- }
-
- // FIXME The exact size should be length if we move to strings or whatever
- char* NewValue = (char*)g_malloc(length+1);
- if( !NewValue) {
- dbg.Verbose(1, "LoadElementValue: Failed to allocate NewValue");
- return;
- }
- NewValue[length]= 0;
-
- item_read = fread(NewValue, (size_t)length, (size_t)1, fp);
- if ( item_read != 1 ) {
- g_free(NewValue);
- Error::FileReadError(fp, "gdcmHeader::LoadElementValue");
- ElVal->SetValue("gdcm::UnRead");
- return;
- }
- ElVal->SetValue(NewValue);
-}
-
-/**
- * \ingroup gdcmHeader
- * \brief Loads the element while preserving the current
- * underlying file position indicator as opposed to
- * to LoadElementValue that modifies it.
- * @param ElVal Element whose value shall be loaded.
- * @return
- */
-void gdcmHeader::LoadElementValueSafe(ElValue * ElVal) {
- long PositionOnEntry = ftell(fp);
- LoadElementValue(ElVal);
- fseek(fp, PositionOnEntry, SEEK_SET);
-}
-
-
-guint16 gdcmHeader::ReadInt16(void) {
- guint16 g;
- size_t item_read;
- item_read = fread (&g, (size_t)2,(size_t)1, fp);
- if ( item_read != 1 )
- throw Error::FileReadError(fp, "gdcmHeader::ReadInt16");
- g = SwapShort(g);
- return g;
-}
-
-guint32 gdcmHeader::ReadInt32(void) {
- guint32 g;
- size_t item_read;
- item_read = fread (&g, (size_t)4,(size_t)1, fp);
- if ( item_read != 1 )
- throw Error::FileReadError(fp, "gdcmHeader::ReadInt32");
- g = SwapLong(g);
- return g;
-}
-
-/**
- * \ingroup gdcmHeader
- * \brief Read the next tag without loading it's value
- * @return On succes the newly created ElValue, NULL on failure.
- */
-
-ElValue * gdcmHeader::ReadNextElement(void) {
- guint16 g;
- guint16 n;
- ElValue * NewElVal;
-
- try {
- g = ReadInt16();
- n = ReadInt16();
- }
- catch ( Error::FileReadError ) {
- // We reached the EOF (or an error occured) and header parsing
- // has to be considered as finished.
- return (ElValue *)0;
- }
-
- // Find out if the tag we encountered is in the dictionaries:
- gdcmDictEntry * NewTag = IsInDicts(g, n);
- if (!NewTag)
- NewTag = new gdcmDictEntry(g, n);
-
- NewElVal = new ElValue(NewTag);
- if (!NewElVal) {
- dbg.Verbose(1, "ReadNextElement: failed to allocate ElValue");
- return (ElValue*)0;
- }
-
- FindVR(NewElVal);
- try { FindLength(NewElVal); }
- catch ( Error::FileReadError ) { // Call it quits
- return (ElValue *)0;
- }
- NewElVal->SetOffset(ftell(fp));
- return NewElVal;
-}
-
-bool gdcmHeader::IsAnInteger(ElValue * ElVal) {
- guint16 group = ElVal->GetGroup();
- guint16 element = ElVal->GetElement();
- string vr = ElVal->GetVR();
- guint32 length = ElVal->GetLength();
-
- // When we have some semantics on the element we just read, and if we
- // a priori know we are dealing with an integer, then we shall be
- // able to swap it's element value properly.
- if ( element == 0 ) { // This is the group length of the group
- if (length == 4)
- return true;
- else
- dbg.Error("gdcmHeader::IsAnInteger",
- "Erroneous Group Length element length.");
- }
-
- if ( group % 2 != 0 )
- // We only have some semantics on documented elements, which are
- // the even ones.
- return false;
-
- if ( (length != 4) && ( length != 2) )
- // Swapping only make sense on integers which are 2 or 4 bytes long.
- return false;
-
- if ( (vr == "UL") || (vr == "US") || (vr == "SL") || (vr == "SS") )
- return true;
-
- if ( (group == 0x0028) && (element == 0x0005) )
- // This tag is retained from ACR/NEMA
- // CHECKME Why should "Image Dimensions" be a single integer ?
- return true;
-
- if ( (group == 0x0028) && (element == 0x0200) )
- // This tag is retained from ACR/NEMA
- return true;
-
- return false;
-}
-
-/**
- * \ingroup gdcmHeader
- * \brief Recover the offset (from the beginning of the file) of the pixels.
- */
-size_t gdcmHeader::GetPixelOffset(void) {
- // If this file complies with the norm we should encounter the
- // "Image Location" tag (0x0028, 0x0200). This tag contains the
- // the group that contains the pixel data (hence the "Pixel Data"
- // is found by indirection through the "Image Location").
- // Inside the group pointed by "Image Location" the searched element
- // is conventionally the element 0x0010 (when the norm is respected).
- // When the "Image Location" is absent we default to group 0x7fe0.
- guint16 grPixel;
- guint16 numPixel;
- string ImageLocation = GetPubElValByName("Image Location");
- if ( ImageLocation == "UNFOUND" ) {
- grPixel = 0x7FE0;
- } else {
- grPixel = (guint16) atoi( ImageLocation.c_str() );
- }
- if (grPixel != 0x7fe0)
- // FIXME is this still necessary ?
- // Now, this looks like an old dirty fix for Philips imager
- numPixel = 0x1010;
- else
- numPixel = 0x0010;
- ElValue* PixelElement = PubElVals.GetElement(grPixel, numPixel);
- if (PixelElement)
- return PixelElement->GetOffset();
- else
- return 0;
-}
-
-gdcmDictEntry * gdcmHeader::IsInDicts(guint32 group, guint32 element) {
- gdcmDictEntry * found = (gdcmDictEntry*)0;
- if (!RefPubDict && !RefShaDict) {
- //FIXME build a default dictionary !
- printf("FIXME in gdcmHeader::IsInDicts\n");
- }
- if (RefPubDict) {
- found = RefPubDict->GetTag(group, element);
- if (found)
- return found;
- }
- if (RefShaDict) {
- found = RefShaDict->GetTag(group, element);
- if (found)
- return found;
- }
- return found;
-}
-
-string gdcmHeader::GetPubElValByNumber(guint16 group, guint16 element) {
- return PubElVals.GetElValue(group, element);
-}
-
-string gdcmHeader::GetPubElValByName(string TagName) {
- return PubElVals.GetElValue(TagName);
-}
-
-/**
- * \ingroup gdcmHeader
- * \brief Parses the header of the file but does NOT load element values.
- */
-void gdcmHeader::ParseHeader(void) {
- ElValue * newElValue = (ElValue *)0;
-
- rewind(fp);
- CheckSwap();
- while ( (newElValue = ReadNextElement()) ) {
- SkipElementValue(newElValue);
- PubElVals.Add(newElValue);
- }
-}
-
-/**
- * \ingroup gdcmHeader
- * \brief Loads the element values of all the elements present in the
- * public tag based hash table.
- */
-void gdcmHeader::LoadElements(void) {
- rewind(fp);
- TagElValueHT ht = PubElVals.GetTagHt();
- for (TagElValueHT::iterator tag = ht.begin(); tag != ht.end(); ++tag)
- LoadElementValue(tag->second);
-}
-
-void gdcmHeader::PrintPubElVal(ostream & os) {
- PubElVals.Print(os);
-}
-
-void gdcmHeader::PrintPubDict(ostream & os) {
- RefPubDict->Print(os);