Meanwhile, there’s been some great research into dealing with high-DPI displays (which the world and its dog have decided to label “retina”). There’s the in-depth analysis by Daan Jobsis which looks at what you can get away with when it comes to compression and quality for “retina” displays: quite a lot, as it turns out.
In fact, you may well be able to double the dimensions of an image while simultaneously bringing down its quality and end up with an image that is smaller in file size than the original, while still looking great on
high-DP..— displays. The guys over at Filament group have labelled this Compressive Images. Nice.
I’m generally fan of solutions that look for ways of avoiding the problem in the first place. Hence my approach to image optimisation for all devices, widescreen or narrow.
Of course this whole issue of responsive (or compressive) images should really only apply to photographic imagery. If you’re dealing with “text as images” …don’t. Use web fonts. If you’re dealing with logos or icons, there are other options, like SVG.
Then there’s the combination of web fonts and iconography. Why not use a small web font containing just the icons you need?
I tried this recently, diligently following Josh’s excellent blog post detailing how to get icon shapes out of Fireworks, into a font editor, and then into an actual font. It works a treat, although I concur with Josh’s suggestion that the technique should really only be implemented using the
::after pseudo-elements in combination with base-64 encoding the font file. That means it won’t work in every single browser, but that’s the point: these icons should be an enhancement, not a requirement.
Having gone through the tortuous steps required to get my Mac all set up with the software required to follow Josh’s tutorial, I then spotted the note at the end of his article that pointed to Icomoon. That turns out to be a fantastic service. You can pick and choose from the icons provided or you can upload your own vector shapes. Then you can assign the unicode slots you want to use for the icons and you can get the resulting font file base-64 encoded. Very, very cool!