ImageGear for C and C++ on Windows v19.4 - Updated
IG_load_tag_CB_register
API Reference Guide > Core Component API Reference > Core Component Functions Reference > Load Functions > IG_load_tag_CB_register

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

Declaration:

 
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AT_ERRCOUNT ACCUAPI IG_load_tag_CB_register(
   LPFNIG_TAG_SET lpfnTagSet,
   LPVOID lpPrivateData
);

Arguments:

Name Type Description
lpfnTagSet LPFNIG_TAG_SET Pointer to callback function to be called with each Tag encountered while loading.
lpPrivateData LPVOID Pointer to private data (passed to callback function).

Return Value:

Returns 0 if successful. Otherwise, returns the number of ImageGear errors that occurred during this function call.

Supported Raster Image Formats:

This function does not process image pixels.

Sample:

JPEG, Filters, FlashPix

Example:

 
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IG_load_tag_CB_register(NULL, NULL);

Remarks:

This function registers a callback function of type LPFNIG_TAG_GET, LPFNIG_TAG_SET, or LPFNIG_TAG_USER_GET.

See the Core Component Callback Functions Reference section. These callback function types are defined by ImageGear to take a certain set of parameters and to return data to you. Your callback function must supply ImageGear with the type of data required by the callback that you choose.

Once you have written a callback function in one of the types listed above, this function should be called to register it. Once registered, your function will be called once for each Tag encountered while loading a file. A "tag" may also be known as an element in the image's header, or as non-image data. The TIFF format popularized the use of the word "tag".

Different file formats have different sets of tags.