How to manipulate diverse meta-informations of image files in PHP

Question

There are diverse formats to add meta-Information to image (and video) files. nearly every digitalcamera add them to fotos. And sometimes people don't want them to be published.

The standards I found so far are:

1. Exif
2. IPTC-NAA
3. XMP

Are there more? (e.g. not image specific, but general meta standard, that can be attached to the end of every file)

Reading the information that is saved, using PHP seems to be possible for the three named formats.

• For XMP: How can I read XMP data from a JPG with PHP?

• For Exif PHP provides functions: https://www.php.net/manual/de/function.exif-read-data.php (but only For JPEG and TIFF, or can Exif data be only attached to those image formats?)

• Also for IPTC: https://www.php.net/manual/de/function.iptcparse.php

But how can the data be manipulated (changed, added)

How can I delete all possible meta-data using PHP? (i.e. all infomation that does not belong to the image itself)

Answer 1

Open and save the image with GD. This should remove all meta data because GD lib cannot handle it.

If that doesn't cut it, try any of

• http://lsolesen.github.com/pel/
• http://ozhiker.com/electronics/pjmt/
• http://php.net/iptcembed