Per discussion with Tim, in order to optimize image download size, especially for Zero, we need to be able to scale down not just the size, but also the quality (jpg) or the number of colors (png/gif). Please add the ability to reduce image download size by reducing quality.
Version: 1.23.0
Severity: enhancement
I think the idea is to postprocess the article HTML in MobileFrontend to replace the img src attributes with ones that include a quality class parameter. Obviously we want to keep the number of quality classes small for optimal cache hit ratio -- I suggested two classes, Yuri suggested three. I showed Yuri a few images scaled with various quality parameters. It seems that for JPEG, ImageMagick -quality 30 is roughly what he is thinking, for a low-quality class.
I'm not sure how devices would be assigned to quality classes, or whether the carrier would influence quality class choice. I suppose feature phones known to lack support for 3G etc. would be given low quality images.