Format for a url that goes to Google image search?

Question

I have a web page which has links at the bottom like this:

- photos of rome
- 

        

Answer 1

http://www.google.com/search?q=&tbm=isch

The tbm=isch is the internal google search parameter that determines what kind of search to perform. There doesn't seem to be any official documentation on it, but this page has a decent write up:

Google Search Request Params

EDIT:

It looks like if you don't include the "/search" part of the string, it fills the google searchbox, but doesn't actually execute the search.