User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.8; rv:20.0) Gecko/20100101 Firefox/20.0 Build ID: 20130326150557 Steps to reproduce: Transition opacity on an image that has transform:scale(0.4) applied. JSFiddle: http://rodneyrehm.de/t/image-smoothing.mov Note: this only happens if there is a small-enough transform:scale() in play. Actual results: The image smoothing during the transition is poor and "fixed" after the transition ended Video: http://jsfiddle.net/fSjUb/3/ Expected results: the smoothing of the image should not be visually apparent.
Possibly related: bug 1024152 and bug 860261. Also visible in attachment 8550808 [details] (testcase for bug 1122885).
I still reproduce in latest nightly (46 from 20160104030217) on Linux/GTK3.