Thread:JoshuaJSlone/@comment-4074115-20150508154341/@comment-131168-20150508172633

The reason it's all single/album covers is I also have a Hello! Project database DohBell (which is currently way out of date as I've ended up spending more time at the wiki), so I'd already gone through the process of getting images from hundreds of those releases and making them the same size (more or less). The database also makes it relatively easy to do something like grab only covers for Berryz Koubou releases, or Morning Musume releases from date X to date Y, things like that. So actually, for the same reason doing something date-based like May-July releases is feasible and not a bad idea.

About the number of covers: as things have been for the last few versions I think it works out to over 300, though there are repeats and most get covered up. I made a program to randomly throw them together--it first lays a layer out very evenly (picked randomly from the list of eligible covers) so at least there's no blank space, then tosses 100 more crazily placed ones on top. For the Sayu / Berryz images I just kind of had to run it over and over until I got some that didn't very obviously have the same cover showing up next to itself, since each only had about 100 covers to work with.