Working with Value Representations

The value representation of a data element indicates the type of data that can be stored in the value field of the data element. There are a number of value representations that are standard for the DICOM file format. In addition to the standard value representations, user-defined value representations may also be added.

LEADTOOLS maintains a table (or list) internally of all available value representations, standard and user defined. In this documentation the table of available value representations will be referred to as the Value Representation Table. Also provided in this documentation is a table of the default values for the standard value representations. To see these default values, refer to the Default Value Representation Table.

LEADTOOLS provides a number of functions for maneuvering through and modifying the Value Representation Table. All functions pertaining to the Value Representation Table have the form L_DicomxxxVR.

For maneuvering through the Value Representation Table, LEADTOOLS provides the following functions:

L_DicomGetFirstVR

L_DicomGetLastVR

L_DicomGetPrevVR

L_DicomGetNextVR

L_DicomGetCountVR

To find specific items, based on either the value representation or an index into the table, use L_DicomFindVR and L_DicomFindIndexVR.

To insert new items in the Value Representation Table, call L_DicomInsertVR.

You can delete individual items from the table using L_DicomDeleteVR, or you can delete all items from the table, using L_DicomResetVR.

To change the name of an item already in the table, call L_DicomSetNameVR.

To determine whether you have a valid pointer to a Value Representation item, call L_DicomExistsVR.

Finally, to reset the Value Representation Table to the default values, use L_DicomDefaultVR.

For more information on value representations, refer to An Overview of the DICOM File Format or the DICOM Standard.