Program: gdcm
Module: $RCSfile: gdcmHeader.cxx,v $
Language: C++
- Date: $Date: 2004/10/12 04:35:46 $
- Version: $Revision: 1.193 $
+ Date: $Date: 2004/10/18 12:49:22 $
+ Version: $Revision: 1.194 $
Copyright (c) CREATIS (Centre de Recherche et d'Applications en Traitement de
l'Image). All rights reserved. See Doc/License.txt or
return lutNbits;
}
-/**
- * \brief builts Red/Green/Blue/Alpha LUT from Header
- * when (0028,0004),Photometric Interpretation = [PALETTE COLOR ]
- * and (0028,1101),(0028,1102),(0028,1102)
- * - xxx Palette Color Lookup Table Descriptor - are found
- * and (0028,1201),(0028,1202),(0028,1202)
- * - xxx Palette Color Lookup Table Data - are found
- * \warning does NOT deal with :
- * 0028 1100 Gray Lookup Table Descriptor (Retired)
- * 0028 1221 Segmented Red Palette Color Lookup Table Data
- * 0028 1222 Segmented Green Palette Color Lookup Table Data
- * 0028 1223 Segmented Blue Palette Color Lookup Table Data
- * no known Dicom reader deals with them :-(
- * @return a RGBA Lookup Table
- */
-uint8_t* Header::GetLUTRGBA()
-{
- // Not so easy : see
- // http://www.barre.nom.fr/medical/dicom2/limitations.html#Color%20Lookup%20Tables
-
-// if Photometric Interpretation # PALETTE COLOR, no LUT to be done
- if ( GetEntryByNumber(0x0028,0x0004) != "PALETTE COLOR " )
- {
- return NULL;
- }
-
- int lengthR, debR, nbitsR;
- int lengthG, debG, nbitsG;
- int lengthB, debB, nbitsB;
-
- // Get info from Lut Descriptors
- // (the 3 LUT descriptors may be different)
- std::string lutDescriptionR = GetEntryByNumber(0x0028,0x1101);
- if ( lutDescriptionR == GDCM_UNFOUND )
- {
- return NULL;
- }
-
- std::string lutDescriptionG = GetEntryByNumber(0x0028,0x1102);
- if ( lutDescriptionG == GDCM_UNFOUND )
- {
- return NULL;
- }
-
- std::string lutDescriptionB = GetEntryByNumber(0x0028,0x1103);
- if ( lutDescriptionB == GDCM_UNFOUND )
- {
- return NULL;
- }
-
- // lengthR: Red LUT length in Bytes
- // debR: subscript of the first Lut Value
- // nbitsR: Lut item size (in Bits)
- int nbRead = sscanf( lutDescriptionR.c_str(), "%d\\%d\\%d",
- &lengthR, &debR, &nbitsR );
- if( nbRead != 3 )
- {
- dbg.Verbose(0, "Header::GetLUTRGBA: trouble reading red LUT");
- }
-
- // lengthG: Green LUT length in Bytes
- // debG: subscript of the first Lut Value
- // nbitsG: Lut item size (in Bits)
- nbRead = sscanf( lutDescriptionG.c_str(), "%d\\%d\\%d",
- &lengthG, &debG, &nbitsG );
- if( nbRead != 3 )
- {
- dbg.Verbose(0, "Header::GetLUTRGBA: trouble reading green LUT");
- }
-
- // lengthB: Blue LUT length in Bytes
- // debB: subscript of the first Lut Value
- // nbitsB: Lut item size (in Bits)
- nbRead = sscanf( lutDescriptionB.c_str(), "%d\\%d\\%d",
- &lengthB, &debB, &nbitsB );
- if( nbRead != 3 )
- {
- dbg.Verbose(0, "Header::GetLUTRGBA: trouble reading blue LUT");
- }
-
- // Load LUTs into memory, (as they were stored on disk)
- uint8_t* lutR = (uint8_t*) GetEntryBinAreaByNumber(0x0028,0x1201);
- uint8_t* lutG = (uint8_t*) GetEntryBinAreaByNumber(0x0028,0x1202);
- uint8_t* lutB = (uint8_t*) GetEntryBinAreaByNumber(0x0028,0x1203);
-
- if ( !lutR || !lutG || !lutB )
- {
- dbg.Verbose(0, "Header::GetLUTRGBA: trouble with one of the LUT");
- return NULL;
- }
- // forge the 4 * 8 Bits Red/Green/Blue/Alpha LUT
-
- uint8_t* LUTRGBA = new uint8_t[1024]; // 256 * 4 (R, G, B, Alpha)
- if ( !LUTRGBA )
- {
- return NULL;
- }
- memset(LUTRGBA, 0, 1024);
-
- // Bits Allocated
- int nb;
- std::string str_nb = GetEntryByNumber(0x0028,0x0100);
- if ( str_nb == GDCM_UNFOUND )
- {
- nb = 16;
- }
- else
- {
- nb = atoi( str_nb.c_str() );
- }
- int mult;
-
- if ( nbitsR == 16 && nb == 8)
- {
- // when LUT item size is different than pixel size
- mult = 2; // high byte must be = low byte
- }
- else
- {
- // See PS 3.3-2003 C.11.1.1.2 p 619
- mult = 1;
- }
-
- // if we get a black image, let's just remove the '+1'
- // from 'i*mult+1' and check again
- // if it works, we shall have to check the 3 Palettes
- // to see which byte is ==0 (first one, or second one)
- // and fix the code
- // We give up the checking to avoid some (useless ?)overhead
- // (optimistic asumption)
- uint8_t* a;
- int i;
-
- a = LUTRGBA + 0;
- for( i=0; i < lengthR; ++i)
- {
- *a = lutR[i*mult+1];
- a += 4;
- }
-
- a = LUTRGBA + 1;
- for( i=0; i < lengthG; ++i)
- {
- *a = lutG[i*mult+1];
- a += 4;
- }
-
- a = LUTRGBA + 2;
- for(i=0; i < lengthB; ++i)
- {
- *a = lutB[i*mult+1];
- a += 4;
- }
-
- a = LUTRGBA + 3;
- for(i=0; i < 256; ++i)
- {
- *a = 1; // Alpha component
- a += 4;
- }
- return LUTRGBA;
-}
-
/**
* \brief Accesses the info from 0002,0010 : Transfert Syntax and TS
* else 1.
git://git.creatis.insa-lyon.fr / gdcm.git / blobdiff