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Re: [RC6] rgb(50%, ..., ...) or rgb(..., 50%, ...) or rgb(..., ..., 50%): fractional value!

From: Alan Gresley <alan@css-class.com>
Date: Thu, 06 Dec 2012 16:42:39 +1100
Message-ID: <50C0304F.1020300@css-class.com>
To: Gérard Talbot <css21testsuite@gtalbot.org>
CC: Rebecca Hauck <rhauck@adobe.com>, Arron Eicholz <arron.eicholz@microsoft.com>, Public CSS test suite mailing list <public-css-testsuite@w3.org>
On 6/12/2012 12:49 PM, "Gérard Talbot" wrote:
>
> Le Mer 5 décembre 2012 19:25, Rebecca Hauck a écrit :

>> Second point:
>> However, does this expose a different weakness in the test?
>
>
> I think it does expose a weakness in the test. An automated checking of
> background-color-* test (software comparing screenshots) would
> eventually report failures that no human eyes would be able to
> see/notice to begin with.
>
> rgb(1%, 1%, 1%) is *not* #020202 in some browsers.
>
>
> rgb(1%, 1%, 1%) is equivalent to #020202 in some other browsers.
>
> Therefore, there is a weakness in the test which can be explained.

This is true for most colors but the human eye can detect the difference 
between rgb(127,127,127) and rgb(128,128,128). This is right at the 
centre of RGB color space (or a RBG-cube).

<!DOCTYPE html>

<style type="text/css">
body {background: rgb(127,127,127); }
div { background: rgb(128,128,128); height: 300px; margin: 100px auto 
100%; }
</style>

<div></div>

Even thought this test shows a layer of dust on the screen, I can still 
detect a difference. Trying scrolling.

Alan


-- 
Alan Gresley
http://css-3d.org/
http://css-class.com/
Received on Thursday, 6 December 2012 05:43:53 GMT

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