Many people only use some sort of content analysis as their research method, isn't this what most people in Critical Discourse Analysis do? So, if you link this research with your methodology this would more than suffice. The whole analysing visual images is interesting too. Which discipline are you in and have you looked at the CDA stuff? Fairclough, Wodak etc? Not too sure of the visual side of things, but think Sarah Pink does stuff on visual ethnography. Would be interested to know what other forum members think...