Embed Message inside Image

[Dysan]

Hi,

Using PHP, is it possible to embed a message inside an image, without it being visible to the viewer? - a bit like a digital signature?

[bokeh]

Yes. It's called Steganography (http://en.wikipedia.org/wiki/Steganography). For a PHP example (http://phpgd.com/articles.php?article=1) check out phpgd.com (http://phpgd.com/)