Data based treemap
Here's the output of my script, currently limited to 27 different images (and thus 27 rows before caching of the same images is implemented). This is always a burden for web browsers and scripts as usually there are max. 6 to 32 total connections open to the same domain in a web browser. Screenshots thus show tiling with 9 and 27 images respectively, with 3 custom gradients and one image without it. Plus mobile versions and (CSV) data used. Nevertheless, I'm working further and this is actually a packing layout challenge with rectangles (usually only circles) and not a treemap chart per se (since you have only one category, no hierarchy). Please discuss (open private chat) for more information.