Google images safe search isn't safe enough for our house. I wanted to find a way of blocking google images without blocking all of Google's services. This solution works as of 12 November 2013. Keep in mind Google is always changing things so this isn't a permanent fix. The thing I found was that a google image search uses a particular web parameter that can be detected by dansguardian and effectively replaced to "break" goole image search.
Here is the code that needs to be added to the urlregexplist
# ban google images