You are correct. You shouldn't be using just the IMG filename for the page title.
One suggestion would be to add alt attributes to your images and use the alt text to populate your titles. The alt text would describe the image it is attached to.
Another suggestion would be to come up with a title for each picture, but still provide an alt attribute with descriptive text and then use the alt text to populate the meta description tag instead. I prefer this one, but it requires more work.
I see you are using HTML5 to produce the same effects provided by the Flash site. I'm not as familiar with HTML5 as I should be, but a lot of your markup doesn't lend to helping crawlers so maybe updating your markup would help. What I mean is: your JavaScript spills out into the bottom of your HTML document and could be included in an external ".js" file. This would help clean up the HTML some. The same is true for your CSS.
One final note: you don't need to use the meta keywords tag any longer if you don't want to. Also, all of your page descriptions are the same for all of your HTML5 pages. You are using a canonical link to your home page, but if you could use different descriptions once you get your title tag issue figured out I believe it will help your pages when indexed individually.