One of the most useful features in Google Analytics for SEO is the keywords data. However, this data is not collected from image search, meaning you're missing out on a potential goldmine of information.
This useful post on dynamical.biz shows how to use custom filters in to get the keywords from google and yahoo image search.
However, the result is a little rough (see this picture) so I thought I'd try and fix it. It seemed a good opportunity to learn how to use both custom filters and regular expressions effectively. With the help of Lunametric's excellent regular expressions guide (http://www.lunametrics.com/regex-book/Regular-Expressions-Google-Analytics.pdf) I worked out how to take this to the next level:
1. Assign the extracted data to 'campaign term' (otherwise known as keyword) rather than user defined value.
2. Changed the medium to organic.
3. Replaced %2B with a space. This one is tricky - you need to use a search and replace, but it won't accept a single space as the replacement character. So you have to type a non-breaking space, which is not so simple - see the link for more details, but on my windows laptop it's alt+fn+1060 using the numeric keypad numbers not the normal numbers, though I could only get this to work by typing it on a text editor and pasting it in (MS Word didn't work). It's weird and tricky but it works. (Thanks to this Chris Abernathy's analytics article for this).
Here's a screenshot showing how the filter should look:
Only other possible improvement I can think of is making the source 'google image' so the searches are aggregated. Could add the domain name to the user defined value so this data is available if you want to look at it.
Any thoughts / further suggestions for improvements?