Bug 46983

Summary: Noise when rendering interlaced PNGs
Product: WebKit Reporter: Mihai Parparita <mihaip>
Component: ImagesAssignee: Nobody <webkit-unassigned>
Status: RESOLVED INVALID    
Severity: Normal CC: ap
Priority: P2 Keywords: InRadar
Version: 528+ (Nightly build)   
Hardware: Mac (Intel)   
OS: OS X 10.6   
Attachments:
Description Flags
Interlaced output none

Mihai Parparita
Reported 2010-10-01 07:24:24 PDT
See test file at http://persistent.info/tmp/interlaced.png (which appears to be a 16-bit/color PNG). When intermediated interlaced output is displayed (see attachment), noise is visible, which may be an indication of uninitialized memory.
Attachments
Interlaced output (471.64 KB, image/png)
2010-10-01 07:25 PDT, Mihai Parparita 		no flags
Details
View All Add attachment proposed patch, testcase, etc.
Mihai Parparita
Comment 1 2010-10-01 07:25:13 PDT
Created attachment 69465 [details] Interlaced output
Alexey Proskuryakov
Comment 2 2010-10-02 20:53:33 PDT
<rdar://problem/8506743>
Alexey Proskuryakov
Comment 3 2010-10-06 15:59:58 PDT
Assuming this report is about Safari, this is not an issue in open source WebKit, so marking INVALID per our policy. Thanks for reporting this problem, it's now being tracked by Apple internally. You could also report it directly to Apple via <http://bugreport.apple.com> (free registration required).
Mihai Parparita
Comment 4 2010-10-06 19:45:42 PDT
I had assumed that, since it happens in both Chrome and Safari, this was in WebKit code (but I don't know if image decompression is handled directly or handed off to OS libraries).
Alexey Proskuryakov
Comment 5 2010-10-07 09:51:16 PDT
I didn't know it happened in Chrome. We certainly think that the Safari problem is below WebKit (in fact, you can see the same when opening the image in Preview.app). > but I don't know if image decompression is handled directly or handed off to OS libraries Some platforms use image decoders that are in WebKit, and others use OS ones. Not sure about Chrome and png specifically.
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