These other formats aren't actually generated during upload, but support
for creating them is there.
Also tune the parameters for generating JPEGs:
* Use Q=85 instead of Q=90 because Q=85 enables 4:2:0 chroma
subsampling, while Q=90 doesn't use subsampling. Subsampling reduces
filesize by ~30% in most cases. It does reduce quality for certain
images, particularly for images with lots of bright red, but in most
cases the quality difference isn't noticeable.
* Enable several MozJPEG-specific options, including trellis
quantization and scan optimization. These reduce filesize without
reducing quality, at the cost of slower encoding times.
This directory contains library code used through Danbooru. This includes things like defining API clients, dealing with
sources, parsing tag searches, storing and resizing images, and so on.
Many of the files here use the Service Object pattern. Instead of putting complex code in models or controllers, it goes
here, in plain old Ruby objects (POROs). This keeps models and controllers simpler, and keeps domain logic isolated and
independent from the database and the HTTP request cycle.