- From: CSS Meeting Bot via GitHub <sysbot+gh@w3.org>
- Date: Thu, 22 Oct 2020 15:27:20 +0000
- To: public-css-archive@w3.org
The CSS Working Group just discussed `Allow impls to not respect exif data if it's after the image data`, and agreed to the following: * `RESOLVED: UAs should ignore exif data that comes after image data` <details><summary>The full IRC log of that discussion</summary> <gregwhitworth> Topic: Allow impls to not respect exif data if it's after the image data<br> <astearns> github: https://github.com/w3c/csswg-drafts/issues/4929<br> <gregwhitworth> TabAtkins: so the image orientation from image value allows you to use the exif data and rotate accordingly<br> <gregwhitworth> TabAtkins: some people noted that the location is flexible. If the exif data can live at the end and you can not initially do the orientation if you're progressively rendering<br> <gregwhitworth> TabAtkins: recommending to not support exif data if the exif data comes after the image data<br> <gregwhitworth> leaverou: any numbers on how common this is?<br> <gregwhitworth> TabAtkins: no<br> <gregwhitworth> TabAtkins: someone mentioned it was less likely, but no strict numbers<br> <smfr> q+<br> <gregwhitworth> chris: cameras have that first and the only cases where this will get messed with is the tools that will shove it at the end<br> <gregwhitworth> TabAtkins: once the image data starts the browser will ignore any other exif data<br> <smfr> i will type<br> <smfr> i find it really weird that css would say anything about how images are encoded<br> <gregwhitworth> astearns: anyone else with a comment on this while we wait for smfr<br> <smfr> i think we treat this as a “bad image” and just let the bad stuff happen<br> <gregwhitworth> TabAtkins: while weird, all browsers are doing this<br> <smfr> also might be hard for implementors: not sure if we can ask our image framework HOW the metadata is ordered<br> <gregwhitworth> astearns: we're doing bad things now because we haven't found exif prior to rendering<br> <smfr> what about a small image which is loaded in 1 go and the EXIF data is still after the image data<br> <gregwhitworth> florian: what about cache scenarios?<br> <gregwhitworth> iank_: I wouldn't bet on that, it's often sometimes slower<br> <smfr> would be OK with a MAY<br> <gregwhitworth> astearns: what if we have UAs may choose to ignore exif data if it isn't before the image data<br> <smfr> don’t want it to be a MUST because of reasons above<br> <gregwhitworth> chris: advise authors to avoid putting it at the end since there isn't interop<br> <gregwhitworth> TabAtkins: then we could go with a should then<br> <gregwhitworth> hober: smfr says he's ok with may<br> <gregwhitworth> florian: not having interop is bad too<br> <TabAtkins> smfr, you okay with SHOULD?<br> <TabAtkins> (probably with an explicit callout to violations being due to image-decoders not reflecting the ordering)<br> <smfr> ok with SHOULD<br> <gregwhitworth> astearns: Should we be "UAs should ignore exif data that comes after image data"<br> <gregwhitworth> Proposed Resolution: UAs should ignore exif data that comes after image data<br> <smfr> q-<br> <gregwhitworth> astearns: I thought loading the image included looking for exif data<br> <gregwhitworth> TabAtkins: yeah, it's not a precise term<br> <futhark> [leaving]<br> <gregwhitworth> RESOLVED: UAs should ignore exif data that comes after image data<br> <astearns> ack fantasai<br> <Zakim> fantasai, you wanted to ask if we should also say authors SHOULD NOT use such images?<br> <gregwhitworth> TabAtkins: I think we should do an authors MUST NOT<br> <gregwhitworth> fantasai: we should give a clear reason as to why to do that<br> <fantasai> s/reason/guidance/<br> <fantasai> s/as to why to/to not/<br> <gregwhitworth> astearns: if we put in author guidance, we should make sure to put in example of why they shouldn't<br> <gregwhitworth> Proposed Resolution: Authors MUST NOT put exif data at the end of the image<br> <gregwhitworth> Resolved: Authors MUST NOT put exif data after the image data<br> <TabAtkins> oh time to rejoin huh<br> <TabAtkins> we're having fun in our breakout, new meeting, csswg is passe<br> <iank_> TabAtkins: do you trigger the rejoin? or do we have to opt-in?<br> <TabAtkins> there's a "return to main call" button on your video<br> <iank_> ah saw the big button thingy<br> <fremy> ScribeNick: fremy<br> </details> -- GitHub Notification of comment by css-meeting-bot Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/4929#issuecomment-714572885 using your GitHub account -- Sent via github-notify-ml as configured in https://github.com/w3c/github-notify-ml-config
Received on Thursday, 22 October 2020 15:27:22 UTC