NEW 227943
EXIF resolution information not applied 
https://bugs.webkit.org/show_bug.cgi?id=227943
Summary EXIF resolution information not applied
Eric Portis
Reported 2021-07-13 23:53:59 PDT
https://cdpn.io/eeeps/debug/LYyRVOR The third image on this page should have an intrinsic size of 1920 x 1280, from its EXIF information. Instead, it has an intrinsic size of 864 x 576. It displays as expected in both Chrome 91 and Firefox 90. Safari passes the relevant Web Platform Tests (https://wpt.fyi/results/density-size-correction?label=master&label=stable&aligned), so there must be an issue with this particular image. Tested on: Safari Version 14.1 (16611.1.21.161.3) Safari Technology Preview Release 127 (Safari 15.0, WebKit 16612.1.18.11.3) macOS Big Sur 11.3 (20E232)
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Simon Fraser (smfr)
Comment 1 2021-07-15 18:43:35 PDT
Firefox and Safari match for me. Chrome shows the image larger. The image EXIF has a DPI of 32.4 pixels per inch.
Eric Portis
Comment 2 2021-07-16 16:49:23 PDT
@smfr: Make sure you test in Firefox 90, which is fairly new and also the first version to ship support for EXIF-based intrinsic sizing. In v90, the third image appears large (as expected), for me. Re: the DPI, a couple of notes... - Binary EXIF stores `XResolution` and `YResolution` as rationals, hence 162/5 in the exiftool code. (A happy side effect of this is perfect precision.) exiftool prints decimals when it reports, though. - The default values, according to the EXIF spec, are 72 dpi, so 32.4 is equivalent to 0.45x/ddpx, in terms of HTML/CSS.
Eric Portis
Comment 3 2021-07-16 16:50:55 PDT
s/ddpx/dppx
Radar WebKit Bug Importer
Comment 4 2021-07-20 23:54:16 PDT
<rdar://problem/80881733>
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