LDicomDS::ChangeTransferSyntax

#include "Ltdic.h"

L_UINT16 LDicomDS::ChangeTransferSyntax(pszUID, nQFactor, uFlags)

L_TCHAR * pszUID;	/* character string */
L_INT32 nQFactor;	/* quality factor */
L_UINT32 uFlags;	/* reserved */

Changes the transfer syntax of the data set.

Parameter	Description
pszUID	Character string that contains the UID of the new Transfer Syntax. Possible values are:
	Value	Meaning
	UID_IMPLICIT_VR_LITTLE_ENDIAN	"1.2.840.10008.1.2"
	UID_EXPLICIT_VR_LITTLE_ENDIAN	"1.2.840.10008.1.2.1"
	UID_EXPLICIT_VR_BIG_ENDIAN	"1.2.840.10008.1.2.2"
	UID_JPEG_BASELINE_1	"1.2.840.10008.1.2.4.50"
	UID_JPEG_EXTENDED_2_4	"1.2.840.10008.1.2.4.51"
	UID_JPEG_LOSSLESS_NONHIER_14	"1.2.840.10008.1.2.4.57"
	UID_JPEG_LOSSLESS_NONHIER_14B	"1.2.840.10008.1.2.4.70"
	UID_JPEG2000_LOSSLESS_ONLY	"1.2.840.10008.1.2.4.90"
	UID_JPEG2000	"1.2.840.10008.1.2.4.91"
	UID_RLE_LOSSLESS	"1.2.840.10008.1.2.5"
nQFactor	The quality factor (Q factor) is a number that determines the degree of loss in the compression process. You can set a value from 2 to 255, where 2 is the highest quality and 255 is the most compression. This parameter only applies when the new transfer syntax will involve compressing pixel data using a lossy compression.
uFlags	Flag that indicates how the compression will be performed. Possible values are:
	Value	Meaning
	DICOM_CHANGETRAN_MINIMIZE_JPEG_SIZE	[0x00000001] If set, and the new transfer syntax uses JPEG compression, the JPEG compression engine will use optimized Huffman tables, which results in better compression, but slower speed.
	DICOM_CHANGETRAN_RESCALE_MODALITY_LUT_WHEN_LOSSY_COMPRESSED	[0x00000002] If set, and the new transfer syntax uses JPEG lossy compression, any modality LUT present will be rescaled to account for changes in minimum and maximum grayscale values due to lossy compression.

Returns

0	SUCCESS
>0	An error occurred. Refer to Return Codes.

Comments

This function will convert the data set's transfer syntax to the transfer syntax specified in pszUID, maintaining all elements and values in the data set.

After this function is called all previous references to data elements in the data set will no longer be valid.

This function is especially useful when sending a C_STORE_REQ message using the LDicomNet::SendCStoreRequest function. The user can match the data set transfer syntax with the transfer syntax of the SCP.

If this function returns the error DICOM_ERROR_WRITE, one of the causes could be that your system is missing the LEADTOOLS file filter LFCMPU.DLL. Specifically, this error will be returned if either the original transfer syntax or the new transfer syntax is one of the following:

UID_JPEG_BASELINE_1
UID_JPEG_EXTENDED_2_4
UID_JPEG_LOSSLESS_NONHIER_14
UID_JPEG_LOSSLESS_NONHIER_14B

Make sure that the LFCMPU.DLL is in the same folder as the other LEAD DLLS. For more information see Files To Be Included With Your Application.

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

Platforms

Win32, x64

See Also

Functions:	LDicomNet::SendCStoreRequest, Class Members
Topics:	Working with Data Sets
	How to Disable the Automatic Loading of the default DICOM IOD Table

Example

#define MAKE_IMAGE_PATH(pFileName) TEXT("C:\\Users\\Public\\Documents\\LEADTOOLS Images\\")pFileName
L_INT LDicomDS_ChangeTransferSyntaxExample()
{
   L_INT       nRet;
   LDicomDS*   pDS;
   pDS = new LDicomDS(NULL);
   nRet = pDS->LoadDS(MAKE_IMAGE_PATH(TEXT("image1.dcm")), 0);
   if(nRet != DICOM_SUCCESS)
      return nRet;
   // Change transfer syntax to explicit VR Big Endian
   nRet = pDS->ChangeTransferSyntax(UID_EXPLICIT_VR_BIG_ENDIAN,0,0);
   if(nRet != DICOM_SUCCESS)
      return nRet;
   // Save the new dataset
   nRet = pDS->SaveDS(MAKE_IMAGE_PATH(TEXT("temp.dcm")), 0);
   if(nRet != DICOM_SUCCESS)
      return nRet;
   delete pDS;
   return DICOM_SUCCESS;
}