Just to clarify, the idea isn't to support or advocate for any particular format, it's to allow devs to specify format types with their images, with fallbacks. Similar to how <source> works with <video>, with the first supported format being used. (Although supporting this functionality doesn't necessarily require a <picture>/<source> format, that's at least an easy touchstone we're familiar with.)
This way a dev could, for example, use SVG or some new responsive format if they're available, with fallbacks to JPEG-XR, then WebP, then JPEG.
See the new use case I added at: https://github.com/ResponsiveImagesCG/ri-usecases/blob/gh-pages/index.html
The point about it being controversial is definitely true, though. I think if we're going to include anything about formats, we have to tread carefully.
On 2012-10-15, at 11:56 AM, François REMY <fremycompany_pub@yahoo.fr> wrote:
> Supporting WebP from Google while not supporting JPEG-XR from Microsoft seems rather difficult to hold position. Based on most tests I’ve been able to read, JPEG-XR and WebP perform almost similarly (slight win for WebP on average), but JPEG-XR is much faster to decode, making it better suited for the web context. Behind that, you get the usual MS vs GOOG debate as none of the two want to implement the other's format.
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> By the way, I don't really grasp why the RespIMG spec should talk about image formats. This is very controversial and could create a lot of high N/S debates unrelated to the core issue (which is: responsive image).
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