ImageGear for C and C++ on Linux v20.0 - Updated
API Reference Guide > Core Component API Reference > Core Component Callback Functions Reference > LPFNIG_TAG_USER_GET

This function has been deprecated and will be removed from the public API in a future release. Please use LPAFT_IG_METAD_ITEM_GET_CB instead.


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        LPVOID lpPrivate, 
        LPAT_MODE lpUserTag, 
        LPAT_MODE lpDataType, 
        LPVOID32 FAR* lpTagData, 
        LPDWORD lpSize 


Name Type Description
lpPrivate LPVOID Far pointer to private data area, which can be used for anything you like, including the storage of the image's HIGEAR handle.
lpIGTag LPAT_MODE Far pointer to an AT_MODE variable to receive a private tag number. Your value must be 32768 or higher.
lpDataType LPAT_MODE Set to an IG_TAG_TYPE_ constant (these are listed in file accucnst.h) specifying the data type for this tag.
lpTagData LPVOID32 FAR* Return a pointer to your data.
lpSize LPDWORD Tell ImageGear the size of your data.

Return Value:

Return TRUE if returning a tag, in which case this callback function will be called again in case you have more tags to supply. Return FALSE if you are not returning a tag and are done returning tags.

Supported Raster Image Formats:

This function does not process image pixels.


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   LPVOID         lpPrivate,     /* Private data passed in */
   LPAT_MODE      lpnIGTag,        /* Tag ID from geartags.h */
   LPAT_MODE      lpType,        /* Type of data lpTag points to */
   LPVOID  FAR*   lpTag,         /* Pointer to tag data */
   LPDWORD        lpSize         /* Size of tag data (bytes) */
/* set Tag ID, data type, length, and pointer to your data */
   *lpSize = 0;
if( (*lpnIGTag-IGTAG_JPG_APPDATA)==12   )       /* supplying only APP13 marker  */
/* supply application marker data */
                        *lpType = IG_TAG_TYPE_RAWBYTES;
                        *lpTag = (LPVOID)(&TestData[0]);
                        *lpSize = sizeof(TestData);
                        return  TRUE;
/* FALSE when no tag being returned */
                      return    FALSE;
IG_save_tag_CB_register( TagGet, TagUserGet, (LPVOID)&dwPrivateFlags );


This function allows you to store a private TIFF tag with the image being saved.

This callback function is registered by calling IG_save_tag_CB_register(). In this callback, you supply a tag number, tag type, and tag data. Note that the value of your private tag number must be higher than 32768.

When ImageGear is going to save a file it will check to see if you have registered any applicable callbacks. If you have registered a callback of type LPFNIG_USER_TAG_GET(), it will be called until you set it to FALSE. While your callback is still set to TRUE, it will add your user-defined tags one at a time to the TIFF image being saved.

lpIGTag is a far pointer to an AT_MODE in which you store a privately defined tag ID#. lpDataType is a pointer to your Tag data type, lpTagData is a pointer to your tag data, and lpSize is the length of your tag data.

This callback function should return TRUE when supplying a tag, in which case it will be called again. Return FALSE when you are done supplying tags. This callback will be called at least once if it has been registered.

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