- From: SVG Working Group Issue Tracker <sysbot+tracker@w3.org>
- Date: Tue, 29 Jun 2010 13:35:48 +0000
- To: public-svg-wg@w3.org
ISSUE-2343: 15.12 Filter primitive ‘feComposite’ formula [SVG 1.1 F2 Last Call] http://www.w3.org/Graphics/SVG/WG/track/issues/2343 Raised by: Erik Dahlström On product: SVG 1.1 F2 Last Call about arithmetic operation of feComposite is mentioned: 'If the arithmetic operation is chosen, each result pixel is computed using the following formula: result = k1*i1*i2 + k2*i1 + k3*i2 + k4' What is especially i1 and i2? My assumption is, that it is the value of the corresponding channel of the input indicated by the attributes in for i1 and in2 for i2? If this is correct, my suggestion is to add something like: ',where i1 and i2 indicate the corresponding pixel channel values of the input images, indicated by the attributes in for i1 and in2 for i2, and k1, k2, k3, k4 indicate the values of the attributes with the same name.' Another suggestion to improve the understanding of the other operations is to add formulas for the other operations as well. This can help authors a lot, because the original article from Porter and Duff is not trivial to find for all readers, for example currently here an online version: http://keithp.com/~keithp/porterduff/p253-porter.pdf Additional suggestion for the related example: Add a generic font-family - Instead of font-family="Verdana" use for example font-family="Verdana, sans-serif" Original mail: http://www.w3.org/mid/201006291243.33346.Dr.O.Hoffmann@gmx.de
Received on Tuesday, 29 June 2010 13:35:49 UTC