/* We need to check if the image already had a description stored. */
if ($desc == null) {
/* The was no description in the image. */
println('Added new IMAGE_DESCRIPTION entry with "%s".', $description);
/*
* In this case we simply create a new PelEntryAscii object to hold
* the description. The constructor for PelEntryAscii needs to know
* the tag and contents of the new entry.
*/
$desc = new PelEntryAscii(PelTag::IMAGE_DESCRIPTION, $description);
/*
* This will insert the newly created entry with the description
* into the IFD.
*/
$ifd0->addEntry($desc);
} else {
/* An old description was found in the image. */
println('Updating IMAGE_DESCRIPTION entry from "%s" to "%s".', $desc->getValue(), $description);
/* The description is simply updated with the new description. */
$desc->setValue($description);
}
/*
* At this point the image on disk has not been changed, it is only
* the object structure in memory which represent the image which has
* been altered. This structure can be converted into a string of
* bytes with the getBytes method, and saving this in the output file
* completes the script.
*/
println('Writing file "%s".', $output);
$file->saveFile($output);
