+ * @return
+ */
+bool gdcmHeader::IsJPEGLossless(void) {
+ gdcmElValue* Element = PubElValSet.GetElementByNumber(0x0002, 0x0010);
+ // faire qq chose d'intelligent a la place de ça
+ if ( !Element )
+ return false;
+ LoadElementValueSafe(Element);
+ const char * Transfert = Element->GetValue().c_str();
+ if ( memcmp(Transfert+strlen(Transfert)-2 ,"70",2)==0) return true;
+ if ( memcmp(Transfert+strlen(Transfert)-2 ,"55",2)==0) return true;
+ return false;
+}
+
+
+/**
+ * \ingroup gdcmHeader
+ * \brief Determines if the Transfer Syntax was already encountered
+ * and if it corresponds to a JPEGExtendedProcess2-4 one.
+ *
+ * @return True when JPEGExtendedProcess2-4 found. False in all other cases.
+ */
+bool gdcmHeader::IsJPEGExtendedProcess2_4TransferSyntax(void) {
+ gdcmElValue* Element = PubElValSet.GetElementByNumber(0x0002, 0x0010);
+ if ( !Element )
+ return false;
+ LoadElementValueSafe(Element);
+ std::string Transfer = Element->GetValue();
+ if ( Transfer == "1.2.840.10008.1.2.4.51" )
+ return true;
+ return false;
+}
+
+/**
+ * \ingroup gdcmHeader
+ * \brief Determines if the Transfer Syntax was already encountered
+ * and if it corresponds to a JPEGExtendeProcess3-5 one.
+ *
+ * @return True when JPEGExtendedProcess3-5 found. False in all other cases.
+ */
+bool gdcmHeader::IsJPEGExtendedProcess3_5TransferSyntax(void) {
+ gdcmElValue* Element = PubElValSet.GetElementByNumber(0x0002, 0x0010);
+ if ( !Element )
+ return false;
+ LoadElementValueSafe(Element);
+ std::string Transfer = Element->GetValue();
+ if ( Transfer == "1.2.840.10008.1.2.4.52" )
+ return true;
+ return false;
+}
+
+/**
+ * \ingroup gdcmHeader
+ * \brief Determines if the Transfer Syntax was already encountered
+ * and if it corresponds to a JPEGSpectralSelectionProcess6-8 one.
+ *
+ * @return True when JPEGSpectralSelectionProcess6-8 found. False in all
+ * other cases.
+ */
+bool gdcmHeader::IsJPEGSpectralSelectionProcess6_8TransferSyntax(void) {
+ gdcmElValue* Element = PubElValSet.GetElementByNumber(0x0002, 0x0010);
+ if ( !Element )
+ return false;
+ LoadElementValueSafe(Element);
+ std::string Transfer = Element->GetValue();
+ if ( Transfer == "1.2.840.10008.1.2.4.53" )
+ return true;
+ return false;
+}
+
+/**
+ * \ingroup gdcmHeader
+ * \brief Determines if the Transfer Syntax was already encountered
+ * and if it corresponds to a RLE Lossless one.
+ *
+ * @return True when RLE Lossless found. False in all
+ * other cases.
+ */
+bool gdcmHeader::IsRLELossLessTransferSyntax(void) {
+ gdcmElValue* Element = PubElValSet.GetElementByNumber(0x0002, 0x0010);
+ if ( !Element )
+ return false;
+ LoadElementValueSafe(Element);
+ std::string Transfer = Element->GetValue();
+ if ( Transfer == "1.2.840.10008.1.2.5" )
+ return true;
+ return false;
+}
+
+/**
+ * \ingroup gdcmHeader
+ * \brief Determines if the Transfer Syntax was already encountered
+ * and if it corresponds to a JPEG200 one.0
+ *
+ * @return True when JPEG2000 (Lossly or LossLess) found. False in all
+ * other cases.
+ */
+bool gdcmHeader::IsJPEG2000(void) {
+ gdcmElValue* Element = PubElValSet.GetElementByNumber(0x0002, 0x0010);
+ if ( !Element )
+ return false;
+ LoadElementValueSafe(Element);
+ std::string Transfer = Element->GetValue();
+ if ( (Transfer == "1.2.840.10008.1.2.4.90")
+ || (Transfer == "1.2.840.10008.1.2.4.91") )
+ return true;
+ return false;
+}
+
+/**
+ * \ingroup gdcmHeader
+ * \brief Predicate for dicom version 3 file.
+ * @return True when the file is a dicom version 3.
+ */
+bool gdcmHeader::IsDicomV3(void) {
+ if ( (filetype == ExplicitVR)
+ || (filetype == ImplicitVR) )
+ return true;
+ return false;
+}
+
+/**
+ * \ingroup gdcmHeader
+ * \brief When the length of an element value is obviously wrong (because
+ * the parser went Jabberwocky) one can hope improving things by
+ * applying this heuristic.
+ */
+void gdcmHeader::FixFoundLength(gdcmElValue * ElVal, guint32 FoundLength) {
+ if ( FoundLength == 0xffffffff)
+ FoundLength = 0;
+ ElVal->SetLength(FoundLength);
+}
+
+/**
+ * \ingroup gdcmHeader
+ * \brief
+ *
+ * @return
+ */
+ guint32 gdcmHeader::FindLengthOB(void) {
+ // See PS 3.5-2001, section A.4 p. 49 on encapsulation of encoded pixel data.
+ guint16 g;
+ guint16 n;
+ long PositionOnEntry = ftell(fp);
+ bool FoundSequenceDelimiter = false;
+ guint32 TotalLength = 0;
+ guint32 ItemLength;
+
+ while ( ! FoundSequenceDelimiter) {
+ g = ReadInt16();
+ n = ReadInt16();
+
+ long l = ftell(fp);
+
+ if (errno == 1)
+ return 0;
+ TotalLength += 4; // We even have to decount the group and element
+
+ if ( g != 0xfffe && g!=0xb00c ) /*for bogus header */ {
+ char msg[100]; // for sprintf. Sorry
+ sprintf(msg,"wrong group (%04x) for an item sequence (%04x,%04x)\n",g, g,n);
+ dbg.Verbose(1, "gdcmHeader::FindLengthOB: ",msg);
+ long l = ftell(fp);
+ errno = 1;
+ return 0;
+ }
+ if ( n == 0xe0dd || ( g==0xb00c && n==0x0eb6 ) ) /* for bogus header */
+ FoundSequenceDelimiter = true;
+ else if ( n != 0xe000 ){
+ char msg[100]; // for sprintf. Sorry
+ sprintf(msg,"wrong element (%04x) for an item sequence (%04x,%04x)\n",n, g,n);
+ dbg.Verbose(1, "gdcmHeader::FindLengthOB: ",msg);
+ errno = 1;
+ return 0;
+ }
+ ItemLength = ReadInt32();
+ TotalLength += ItemLength + 4; // We add 4 bytes since we just read
+ // the ItemLength with ReadInt32
+
+ SkipBytes(ItemLength);
+ }
+ fseek(fp, PositionOnEntry, SEEK_SET);
+ return TotalLength;
+}
+
+/**
+ * \ingroup gdcmHeader
+ * \brief
+ *
+ * @return
+ */
+ void gdcmHeader::FindLength (gdcmElValue * ElVal) {
+ guint16 element = ElVal->GetElement();
+ guint16 group = ElVal->GetGroup();
+ std::string vr = ElVal->GetVR();
+ guint16 length16;
+ if( (element == 0x0010) && (group == 0x7fe0) ) {
+ dbg.SetDebug(0);
+ dbg.Verbose(2, "gdcmHeader::FindLength: ",
+ "on est sur 7fe0 0010");
+ }
+
+ 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);
+
+ guint32 length32 = ReadInt32();
+ if ( (vr == "OB") && (length32 == 0xffffffff) ) {
+ ElVal->SetLength(FindLengthOB());
+ return;
+ }
+ FixFoundLength(ElVal, length32);
+ 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 big 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 consists in waiting 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 to 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 already 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 have got our
+ // hands on a big endian encoded file: we switch the swap code to
+ // big endian and proceed...
+ if ( (element == 0x0000) && (length16 == 0x0400) ) {
+ if ( ! IsExplicitVRBigEndianTransferSyntax() ) {
+ dbg.Verbose(0, "gdcmHeader::FindLength", "not explicit VR");
+ errno = 1;
+ return;
+ }
+ 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 = GetDictEntryByNumber(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) {
+ 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);
+}
+
+/**
+ * \ingroup gdcmHeader
+ * \brief
+ *
+ * @return
+ */
+ void gdcmHeader::SkipBytes(guint32 NBytes) {
+ //FIXME don't dump the returned value
+ (void)fseek(fp, (long)NBytes, SEEK_CUR);
+}
+
+/**
+ * \ingroup gdcmHeader
+ * \brief
+ * @param ElVal
+ * @return
+ */
+ void gdcmHeader::SkipElementValue(gdcmElValue * ElVal) {
+ SkipBytes(ElVal->GetLength());
+}
+
+/**
+ * \ingroup gdcmHeader
+ * \brief
+ * @param NewSize
+ * @return
+ */
+ 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 content if it's length is not bigger
+ * than the value specified with
+ * gdcmHeader::SetMaxSizeLoadElementValue()
+ */
+void gdcmHeader::LoadElementValue(gdcmElValue * ElVal) {
+ size_t item_read;
+ guint16 group = ElVal->GetGroup();
+ std::string vr = ElVal->GetVR();
+ guint32 length = ElVal->GetLength();
+ bool SkipLoad = false;
+
+ fseek(fp, (long)ElVal->GetOffset(), SEEK_SET);
+
+ // FIXME Sequences not treated yet !
+ //
+ // Ne faudrait-il pas au contraire trouver immediatement
+ // une maniere 'propre' de traiter les sequences (vr = SQ)
+ // car commencer par les ignorer risque de conduire a qq chose
+ // qui pourrait ne pas etre generalisable
+ // Well, I'm expecting your code !!!
+
+ 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).
+ // Well ...
+ // Actually (fffe e000) tells us an Element is beginning
+ // (fffe e00d) tells us an Element just ended
+ // (fffe e0dd) tells us the current SEQuence just ended
+
+ if( group == 0xfffe )
+ SkipLoad = true;
+
+ if ( SkipLoad ) {
+ ElVal->SetLength(0);
+ ElVal->SetValue("gdcm::Skipped");
+ return;
+ }
+
+ // When the length is zero things are easy:
+ if ( length == 0 ) {
+ ElVal->SetValue("");
+ return;
+ }
+
+ // The elements whose length is bigger than the specified upper bound
+ // are not loaded. Instead we leave a short notice of the offset of
+ // the element content and it's length.
+ if (length > MaxSizeLoadElementValue) {
+ std::ostringstream s;
+ s << "gdcm::NotLoaded.";
+ s << " Address:" << (long)ElVal->GetOffset();
+ s << " 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.