- From: Alex Danilo <alex@abbra.com>
- Date: Fri, 25 Feb 2011 11:13:09 +1100
- To: Rik Cabanier <cabanier@gmail.com>
- Cc: Anthony Grasso <Anthony.Grasso@cisra.canon.com.au>, Dean Jackson <dino@apple.com>, Alistair MacDonald <al@bocoup.com>, Rik Cabanier <cabanier@adobe.com>, Cameron McCormack <cam@mcc.id.au>, Brad Kemper <brad.kemper@gmail.com>, www-style list <www-style@w3.org>, "public-fx@w3.org" <public-fx@w3.org>
Hi Rick, Yes, that's correct. In SVG as specified, it could be <g comp-op="multiply">...</g> or use inline style as you wrote or applied to individual objects, etc. Although, there's no real need for 'blend:layer' in your example, but the overall idea is right. Alex --Original Message--: > > >Hi Alex, > > > > >to make sure I'm not confused. > > >This is a filter: > ><svg version="1.1" xmlns="http://www.w3.org/2000/svg"> > <defs> > <filter id="srcLoadedOverlay"> > <feImage xlink:href="url(#canvas0)" result="img1" /> > <feImage xlink:href="url(#canvas1)" result="img2" /> > <feImage xlink:href="url(#canvas2)" result="img3" /> > <feBlend in="img1" in2="img2" result="blend1" mode="multiply" /> > <feBlend in="blend1" in2="img3" mode="lighten" /> > </filter> > </defs> ></svg> > >and this would be a property: > ><html> > >... > ><body> > >.... <- backdrop > ><div style="blend: layer;"> <- group A > > ... <- text, images, etc > > <div style="blend: multiply;"> <- group B > > .. <- text, images, etc > > </div> > ></div> > >Rik > >On Thu, Feb 24, 2011 at 3:53 PM, Alex Danilo <alex@abbra.com> wrote: > >Hi Anthony and all, > >--Original Message--: >>Just adding to what Alex said (see below)... >> >> >>>-----Original Message----- > >>><snip/> >>> >>>Perhaps that should serve as something to look at. This was researched >>>extensively at the time, and a property works far better than the SVG >>>filter mechanism when combining a lot of objects for blending. >>> >> >>This is because the background is included twice when using filters to perform compositing. This leads to incorrect results - the output tends to be darker than expected. > >Ignoring side-effects, one of the main advantages of a property >over a filter is no need for any sort of intermediate bitmap. > >The object being blended can be rasterized and alpha blended >with the correct blend mode directly to the canvas. So the >performance is significantly higher, especially if you are >trying to composite lots of graphics on top of live HD video >where memory bandwidth actually matters. > >Alex > > > > >
Received on Friday, 25 February 2011 01:45:59 UTC