It depends on what kind of "visuals" you are dealing with and the theoretical/methodological lens of your work. Some I use in my own work and recommend:
Reading Images: The Grammar of Visual Design, Gunther R. Kress, Theo van Leeuwen
Psychology Press, 1996.
Visual Methodologies: An Introduction to Researching with Visual Materials, by Gillian Rose
Doing Visual Ethnography, by Sarah Pink, 2013 (this is not exactly about visual analysis, but it covers some aspects of it in the context of ethnography)
Great question, but like Lode and Aline comment, it definitely depends on the lens. There is not an ultimate approach to visual analysis. Most of the books listed here apply sociological lens to their analysis. If you map the influences of most of these works, they rely pretty much on:
The perceptionists: Marr, Gibson, Gestalt, etc...
Previous works on visual grammar. For example, Kress and Van Leuween rely a lot on the work of Donis Dondis. They also rely on the work of art theorists like Arnheim or Gombrich.
The problem that I find with these works is that they are quite limited and tend to ignore factors that come with production expertise in favour of inherited theoretical perspectives (this is the case of Kress, for example, a scholar that has been criticised to be almost evangelical about the work of Halliday). Rose tries to prevent this situation on her framework, but I personally think that a general "visual analysis" is really hard to do. Another important element to mention is that these approaches to visual analysis are based on visual perception models that have been already revised (spotlight vs scattered attention) and tend to ignore other very rich semiotic traditions (Charles Peirce, Morris, etc.).
If I was you, I would try to look for approaches in predominately visual disciplines (design, arts), I would look for semiotic analysis (not just "social semiotics" that is just one approach) and then I would look for a framework (e.g., Rose).