L_DicomSetVOILUT

#include "ltdic.h"

L_LTDIC_API L_UINT16 L_DicomSetVOILUT(hDS, uVOILUTIndex, pVOILUTAttributes, pLUTData, uDataSize, uFlags)

HDICOMDS hDS;	/* a DICOM handle */
L_UINT uVOILUTIndex;	/* the VOI LUT index*/
pDICOMVOILUTATTRIBS pVOILUTAttributes;	/* pointer to a VOI LUT attributes structure */
L_UINT16 *pLUTData;	/* pointer to the input buffer */
L_UINT uDataSize;	/* size of the input buffer */
L_UINT uFlags;	/* reserved for future use */

Sets the attributes that describe the VOI LUT.

Parameter	Description
hDS	A DICOM handle.
uVOILUTIndex	Index to the VOI LUT to be set. According to the DICOM standard one or more items could exist under one VOI LUT Sequence (0028,3010), use this index to specify which item to update. This index is zero-based.
pVOILUTAttributes	Pointer to a structure containing the VOI LUT attributes to set.
pLUTData	Pointer to the buffer that holds the "LUT Data" (0028,3006), this pointer cant be NULL.
uDataSize	Size of the buffer pointed to by pLUTData , cant be 0.This value should at least equal pVOILUTAttributes->LUTDescriptor.uNumberOfEntries.
uFlags	Reserved for future use. Pass 0.

Returns

0	The function was successful.
>0	An error occurred. Refer to Return Codes.

Comments

This function will set the attributes of the VOI LUT. Before calling this function, initialize pVOILUTAttributes->uStructSize to be sizeof(DICOMVOILUTATTRIBS) and initialize all the members of the structure.

The size of the input buffer should at least equal the number of entries in the lookup table.

According to the DICOM standard pVOILUTAttributes->LUTDescriptor. uNumberOfEntries should be set to 0 if the number of entries in the lookup table is 2^16, however you should NOT do that when calling this function. This function will handle correctly setting the value inside the dataset.

Required DLLs and Libraries

LTDIC

For a listing of the exact DLLs and Libraries needed, based on the toolkit version, refer to Files To Be Included With Your Application

See Also

Functions:	L_DicomGetWindowCount, L_DicomGetVOILUTCount, L_DicomGetWindow, L_DicomSetWindow, L_DicomDeleteWindow, L_DicomGetVOILUT, L_DicomGetVOILUTData, L_DicomDeleteVOILUT
Topics:	LUT Encoding Overview
	LUT Encoding: VOI LUT

Example

This example will add a new VOI LUT to the dataset or replace the existing one(s)

#define SET_SIZE(p) (p)->uStructSize = sizeof(*(p));

L_INT DicomSetVOILUTExample(HDICOMDS hDicomDS, L_BOOL bAdd)
{
   DICOMVOILUTATTRIBS   VOILUTAttribs ={0};
   L_UINT16             uRet;
   L_UINT               uVOILUTCount=0;
   L_UINT16             *pVOILUTData = NULL;
   L_UINT               uDataSize = 0;
   L_UINT               uLUTIndex;
   L_UINT               uNewLUTIndex = 0;

   // Remember  to set the size for each structure
   SET_SIZE(&VOILUTAttribs);
   SET_SIZE(&VOILUTAttribs.LUTDescriptor);

   // Get the number of VOI LUT(s) in the file
   uRet = L_DicomGetVOILUTCount(hDicomDS,&uVOILUTCount);
   if(uRet != DICOM_SUCCESS)
      return uRet;

   if(uVOILUTCount>0)
   {
      // Get he attributes of  the first VOI LUT
      uRet = L_DicomGetVOILUT(hDicomDS,0,&VOILUTAttribs,sizeof(DICOMVOILUTATTRIBS),0);
      if(uRet != DICOM_SUCCESS)
         return uRet;

      uDataSize = VOILUTAttribs.LUTDescriptor.uNumberOfEntries;
      pVOILUTData = (L_UINT16*)malloc(uDataSize* sizeof(L_UINT16));
      if(!pVOILUTData)
         return DICOM_ERROR_MEMORY;

      // Get the LUT data
      uRet = L_DicomGetVOILUTData(hDicomDS,0,pVOILUTData,uDataSize,0);
      if(uRet != DICOM_SUCCESS)
      {
         free(pVOILUTData);
         return uRet;
      }

      // Remap the data
      for(uLUTIndex = 0; uLUTIndex <= (uDataSize-1); uLUTIndex++)
         pVOILUTData[uLUTIndex] = pVOILUTData[uLUTIndex]/2;
   }
   else
   {
      // Define our own LUT
      VOILUTAttribs.LUTDescriptor.nFirstStoredPixelValueMapped = 0;
      VOILUTAttribs.LUTDescriptor.uEntryBits                   = 16;
      VOILUTAttribs.LUTDescriptor.uNumberOfEntries             = 0x10000;
      uDataSize = VOILUTAttribs.LUTDescriptor.uNumberOfEntries;
      pVOILUTData = (L_UINT16*)malloc(uDataSize* sizeof(L_UINT16));
      if(!pVOILUTData)
         return DICOM_ERROR_MEMORY;

      memset(pVOILUTData,0,uDataSize* sizeof(L_UINT16));
      for(uLUTIndex = 0; uLUTIndex<= (uDataSize-1); uLUTIndex++)
         pVOILUTData[uLUTIndex] = (L_UINT16)uLUTIndex;
   }
   uNewLUTIndex = uVOILUTCount;
   if(!bAdd)
   {
      // Delete existing LUT
      uRet = L_DicomDeleteVOILUT(hDicomDS,0);
      if(uRet != DICOM_SUCCESS)
      {  
         free(pVOILUTData);
         return uRet;
      }
      uNewLUTIndex = 0 ;
   }

   // Set the new LUT
   uRet = L_DicomSetVOILUT(hDicomDS,uNewLUTIndex,&VOILUTAttribs,pVOILUTData,uDataSize,0);

   if(pVOILUTData)
      free(pVOILUTData);
   return uRet;
}