Modify JPEG Exif Headers with ONLY PHP

[Matias]

Using the exif functions in php you can read the exif hearers/comments that are embeded within an image or media type.

The header comments are then fetched as an array from the image. Does anyone know how to add exif headers in images using PHP?

I found two libraries that can do this: PEL and PHP JPEG Toolkit. Both I am sure do the job and PURE PHP, but it is annoying to have the both libraries because they cannot be very well integrated into my application, plus they both come with an abundance of features which I am not interested in.

So what I am asking here is does anyone know how to do this manually, therefore doing it by hand? I know this is possible since both of the libraries are pure php. So any ideas?

[redbullmarky]

can you not simply lift out the relevent code from the PEL/JPEG Toolkit, or at least use them to suss out how it works?

[Matias]

Its not that easy, have you ever taken a look at their source