PHP - getting a site's favicon and converting it to png if necessary

Question

For any given site "example.domain.tld" or merely "domain.tld" I need to do the following in PHP:

• If the site has a favicon, get it wherever it is
  • If it is not already a PNG, convert it to PNG
  • Save it to /favicons/example.domain.tld.png
• If the site has no favicon, do nothing.

Any ideas? I'm being stumped by the unreliable fileformat and location of the favicons, but if at all possible I want to avoid downloading the entire source of the page with file_get_contents in order to find it in the headers. Also converting to png seems nontrivial.

Thanks,

Mala

Answer 1

As is typical, I found a passable solution shortly after asking the question - let google do the work for you:

http://www.google.com/s2/favicons?domain=URL

returns a 16x16 png