Edit product image dynamically

[kaktus.m]

Hello everyone,

I am trying to edit the image of one product in my shop dynamically. I want the personalized image to appear at the shopping cart, the product page and at the ordering process. Every cart id and every attribute can have a personalized image.

The question is, which files do I have to edit? Do I have to work on the template or with an override of a controller? I just want to find the files and lines of code where the image is handled and put into the cart, product or the ordering process.

Thanks for any help in advance!