Bug 193018 - Incorrect blur with large radius
Summary: Incorrect blur with large radius
Status: NEW
Alias: None
Product: WebKit
Classification: Unclassified
Component: Layout and Rendering (show other bugs)
Version: Safari 12
Hardware: Mac macOS 10.14
: P2 Normal
Assignee: Nobody
URL:
Keywords: InRadar
Depends on:
Blocks:
 
Reported: 2018-12-23 17:45 PST by Jonathan Deutsch
Modified: 2022-07-01 16:10 PDT (History)
4 users (show)

See Also:

Attachments
Screenshot of incorrect and correct renderings (551.15 KB, image/png)
2018-12-23 17:45 PST, Jonathan Deutsch 		no flags Details
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Description Jonathan Deutsch 2018-12-23 17:45:41 PST 
Created attachment 358033 [details]
Screenshot of incorrect and correct renderings

A blur with a large radius shows graphical corruption.  This can be reproduced very simply via:

<div style="background-color: rgb(255, 235, 200);  width: 450px; height: 446px; filter: blur(75px);"></div>

Please see the attached screenshot. It appears pink!

There are various blur values that can make it look good or bad; I found 68px looks fine but 69px looks incorrect.

One workaround is to use a "transform:rotateY(0deg)" style, but this isn't a valid workaround for us in all cases for other reasons.

This affects Tumult Hype (http://tumult.com/hype/).
Comment 1 Brent Fulgham 2022-07-01 16:10:12 PDT 
Still happens on macOS 13.
Comment 2 Radar WebKit Bug Importer 2022-07-01 16:10:21 PDT 
<rdar://problem/96319816>