Complex map as seat booking system

I already know how to make a seat booking system in PHP using checkboxes as seats. I used this tutorial. The result is something like this: http://ift.tt/1OZQfKE.

Now I want to transform all the checkboxes in this map:

The user would click on a seat and it would become yellow (selected). After confirmation it would become red (reserved).

But I have no idea how separate all seats of this static image and transform them in separate "checkboxes". Could you give me a start point or something like that? I have no idea where to start looking.