Bug 89849

Summary: Use InterpolationLow on chromium-android
Product: WebKit Reporter: Adam Barth <abarth>
Component: New BugsAssignee: Adam Barth <abarth>
Status: RESOLVED FIXED    
Severity: Normal CC: eric, qinmin, senorblanco, webkit.review.bot
Priority: P2    
Version: 528+ (Nightly build)   
Hardware: Unspecified   
OS: Unspecified   
Bug Depends on:    
Bug Blocks: 66687    
Attachments:
Description Flags
Patch
none
Patch
none
Patch for landing none

Adam Barth
Reported 2012-06-24 21:55:05 PDT
Use InterpolationMedium on chromium-android
Attachments
Patch (2.87 KB, patch)
2012-06-24 21:56 PDT, Adam Barth 		no flags
DetailsFormatted DiffDiff
Patch (2.85 KB, patch)
2012-06-25 10:12 PDT, Adam Barth 		no flags
DetailsFormatted DiffDiff
Patch for landing (2.86 KB, patch)
2012-06-25 10:22 PDT, Adam Barth 		no flags
DetailsFormatted DiffDiff
Show Obsolete (2) View All Add attachment proposed patch, testcase, etc.
Adam Barth
Comment 1 2012-06-24 21:56:32 PDT
Created attachment 149236 [details] Patch
Min Qin
Comment 2 2012-06-24 22:39:05 PDT
LGTM. Thanks for the patch
Stephen White
Comment 3 2012-06-25 09:18:42 PDT
Comment on attachment 149236 [details] Patch Medium and Low both map to bilinear interpolation on the Skia path. While this path is fast, it does generate some pretty ugly aliasing, especially noticeable when downsampling (e.g., twinkling during animation). This decision should really be looked at by a person on the Chrome/Android team (unless Min Qin is, I'm not sure from the ChangeLog).
Adam Barth
Comment 4 2012-06-25 09:21:13 PDT
Yeah, Min Qin is works on chromium-android and originally made this change to the chromium-android branch. I can't speak to whether this is a good idea, but it is what's currently happening on the chromium-android branch.
Min Qin
Comment 5 2012-06-25 09:41:51 PDT
On chrome on android, we noticed that there are lots of white blocks when scrolling image heavy sites. The problem is caused by slow image decoding and resampling. Changing to bilinear interpolation greatly increase the resampling speed (almost unnoticeable). The display for android devices is comparatively small (4'-10') compared to that of 20'-30' desktop. Decent image quality degration is tolerable on such small screens.
Stephen White
Comment 6 2012-06-25 09:55:11 PDT
(In reply to comment #5) > On chrome on android, we noticed that there are lots of white blocks when scrolling image heavy sites. The problem is caused by slow image decoding and resampling. Changing to bilinear interpolation greatly increase the resampling speed (almost unnoticeable). > The display for android devices is comparatively small (4'-10') compared to that of 20'-30' desktop. Decent image quality degration is tolerable on such small screens. OK, cool. In that case, could I ask that you use Low rather than Medium? Although they currently both do linear, I have some plans to implement a new resampling method and map Medium to it.
Min Qin
Comment 7 2012-06-25 10:03:14 PDT
Thanks for the update. Adam, would you please make the corresponding change in upstream?
Adam Barth
Comment 8 2012-06-25 10:12:01 PDT
Created attachment 149313 [details] Patch
Adam Barth
Comment 9 2012-06-25 10:12:18 PDT
Done.
Daniel Bates
Comment 10 2012-06-25 10:20:25 PDT
Comment on attachment 149313 [details] Patch View in context: https://bugs.webkit.org/attachment.cgi?id=149313&action=review OK > Source/WebCore/ChangeLog:15 > + non-noticable on the trace. Nit: noticable => noticable [sic] (since the word noticeable is misspelled)
Adam Barth
Comment 11 2012-06-25 10:22:10 PDT
Created attachment 149316 [details] Patch for landing
WebKit Review Bot
Comment 12 2012-06-25 15:01:43 PDT
Comment on attachment 149316 [details] Patch for landing Clearing flags on attachment: 149316 Committed r121184: <http://trac.webkit.org/changeset/121184>
WebKit Review Bot
Comment 13 2012-06-25 15:01:57 PDT
All reviewed patches have been landed. Closing bug.
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