Users are unsatisfied with current quality of images downscaled by filter-media. This leads to using workarounds like creating higher resolution thumbnails and letting the user's browser downscale the image, which is bandwidth-inefficient. The right solution would be to find a better downscaling method.
One proposed option would be to use the Apache-licensed, Maven-dwelling, GitHub-using pure-Java Imgscalr library:
The current code that needs to be changed is here:
and in BrandedPreviewJPEGFilter.java