feTurbulence returns "biased" values? from Jasper van de Gronde on 2010-04-26 (www-svg@w3.org from April 2010)

From: Jasper van de Gronde <th.v.d.gronde@hccnet.nl>
Date: Mon, 26 Apr 2010 14:06:44 +0200
To: www-svg <www-svg@w3.org>
Message-ID: <4BD581D4.3030107@hccnet.nl>

I was looking at the distribution of the color values produced by 
feTurbulence (type=fractalNoise) and found that they are centered around 
0.75 (approximately) instead of 0.5. This seems to be true for Inkscape 
as well as Batik. I've also checked the implementation in Inkscape 
against the code in the specification, and it seems to match.

Every non-SVG example of Perlin noise I've been able to findproduces 
values centered around 0.5, which seems more logical. Any idea where the 
discrepancy comes from? Is this by design? Am I missing something?

Received on Monday, 26 April 2010 12:07:20 UTC