[Webkit-unassigned] [Bug 111177] feGaussianBlur shows banding under certain circumstances

[bugzilla-daemon at webkit.org]

https://bugs.webkit.org/show_bug.cgi?id=111177


Florin Malita <fmalita at chromium.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |fmalita at chromium.org




--- Comment #6 from Florin Malita <fmalita at chromium.org>  2013-03-02 12:01:45 PST ---
(In reply to comment #4)
> Created an attachment (id=191036)
 --> (https://bugs.webkit.org/attachment.cgi?id=191036&action=review) [details]
> Screenshot using Pixie
> 
> This screenshot shows the banding (alternation of darker and brighter bands) using Pixie. If SVG is supposed to replace flash such details count.

So the way I interpret this, the complaint in not strictly related to the presence of bands (they're unavoidable withing a discrete colorspace), but to their non-monotonic nature (lighter-darker-lighter instead of lighter-darker-darkerstill).

AFAICT the color component difference between adjacent bands is not larger than one (as expected), but the alternation is indeed non-monotonic: #565656 -> #575757 -> #565656 -> #555555 -> #545454 -> #555555.

> I expect a smooth gradient without such alternations.

That may be the root of the problem though: this is a Gaussian blur, not a gradient. I'm no feGaussianBlur expert, but your expectation may be unfounded.

I haven't tested IE and FF can't handle the samples, but Opera definitely implements feGaussianBlur similarly.

-- 
Configure bugmail: https://bugs.webkit.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug.