IG_ISIS_tag_get

Get current value of a tag of type long.

Declaration:

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AT_ERRCOUNT ACCUAPI IG_ISIS_tag_get_long( HISISDRV hDriver, AT_MODE nTag, WORD wIndex, LPLONG lplValue );

Arguments:

hDriver	The handle to the driver.
nTag	Specifies the type long tag for which to return the current value.
wIndex	Specifies the index of the element to get. Most tags have only one element, in which case wIndex must be zero. Use IG_ISIS_tag_get_length to determine how many elements a tag contains.
lplValue	Points to the current value of the tag after this function completes.

Return Value:

Returns the number of ImageGear errors that occurred during this function call. If there are no errors, the return value is IGE_SUCCESS.

Supported Raster Image Formats:

This function does not process image pixels.

Remarks:

The IG_ISIS_tag_get_long function retrieves the long value that is the current value of the specified tag.

Use IG_ISIS_tag_get_long to retrieve the current value of the type long tag specified in nTag. Use IG_ISIS_tag_get_length to get the number of elements in the tag. If the tag has only one element, wIndex must be zero. If the tag has multiple elements (such as IG_ISIS_TAG_GAMMA_TABLE1), loop on IG_ISIS_tag_get_long to obtain all elements of the current value of the tag.

Use of IG_ISIS_tag_get_long on a tag other than one of type long, short, or byte is undefined. At best, this will cause an invalid return value or a operating system error message, and at worst will cause the system to crash.

Example:

The following example gets the value of each element of a multiple value tag and puts them into an array:

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BYTE caGamma[256]; DWORD dwCount; LONG lValue;IG_ISIS_tag_get_length(hDriver, IG_ISIS_TAG_GAMMA_TABLE1, &dwCount); while (dwCount--) {IG_ISIS_tag_get_long(hDriver, IG_ISIS_TAG_GAMMA_TABLE1, dwCount, &lValue); caGamma[ulCount] = (BYTE) lValue; } /* Now that you have the values in an array, you can do something / / with them in your own function, such as: */ showGamma(caGamma);

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BYTE caGamma[256];
DWORD dwCount;
LONG lValue;IG_ISIS_tag_get_length(hDriver, IG_ISIS_TAG_GAMMA_TABLE1, &dwCount);
while (dwCount--) {IG_ISIS_tag_get_long(hDriver, IG_ISIS_TAG_GAMMA_TABLE1, dwCount, &lValue);
        caGamma[ulCount] = (BYTE) lValue;
}
/* Now that you have the values in an array, you can do something                                                                                                               */
/* with them in your own function, such as:                                                     */
showGamma(caGamma);