Bug 156488 - putImageData needs to premultiply input
Summary: putImageData needs to premultiply input
Alias: None
Product: WebKit
Classification: Unclassified
Component: Canvas (show other bugs)
Version: WebKit Nightly Build
Hardware: Unspecified Unspecified
: P2 Normal
Assignee: Dean Jackson
Keywords: InRadar
Depends on:
Reported: 2016-04-11 19:43 PDT by Dean Jackson
Modified: 2016-04-11 19:57 PDT (History)
4 users (show)

See Also:

Patch (4.94 KB, patch)
2016-04-11 19:49 PDT, Dean Jackson
zalan: review+
Details | Formatted Diff | Diff

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Description Dean Jackson 2016-04-11 19:43:52 PDT
I made a mistake in r187534, where I updated putImageData to use the Accelerate framework. The iOS path accidentally unpremultiplied the incoming data, rather than premultiplying it.
Comment 1 Radar WebKit Bug Importer 2016-04-11 19:44:17 PDT
Comment 2 Dean Jackson 2016-04-11 19:45:11 PDT
Comment 3 Dean Jackson 2016-04-11 19:49:08 PDT
Created attachment 276201 [details]
Comment 4 Jon Lee 2016-04-11 19:51:28 PDT
What's the impact on the Animometer Images test?
Comment 5 Dean Jackson 2016-04-11 19:52:36 PDT
(In reply to comment #4)
> What's the impact on the Animometer Images test?

Should be zero. We're still doing the same sets of operations, just multiplying rather than dividing. And this is iOS only.
Comment 6 Dean Jackson 2016-04-11 19:57:26 PDT
Committed r199330: <http://trac.webkit.org/changeset/199330>