The O'Reilly Access Cookbook by Ken Getz, Paul Litwin, & Andy Baron has code to do a merge to Word from Access. What do you mean by merge image? Are you storing a jpg or gif in your access table that you want to merge?
Now that I understand the problem, it's that much more interesting. Fresh out of a self paced Access course, I'm knee deep in my first application, which includes several mail merges (code courtesy of Access Cookbook). Once the path is merged into the word doc, it would seem possible to kick off a word macro or VBA script that imports the picture using the path. Beyond my limited skills, though.