On Wed, Apr 16, 2014 at 5:27 AM, Chris Lilley <chris@w3.org> wrote: > Hello Tab, > > Tuesday, April 15, 2014, 8:54:31 PM, you wrote: > > > On Tue, Apr 15, 2014 at 9:54 AM, Tavmjong Bah <tav.w3c@gmail.com> wrote: > > >> As Thomas eludes to, scaling should properly done in a linear color > >> space. > > Yes. > > >> To see why, scale the following SVG up and down in your browser > >> of choice: > >> > >> http://tavmjong.free.fr/SVG/SCALING/scaling_test.svg > >> > >> If your display is calibrated to srgb, the top two squares should be the > >> same color as the bottom right square. As you zoom in, the squares will > >> become darker due to the averaging being done in the srgb color space > >> (and not by your eye!). But this is not as important as at least showing > >> the lines when down scaling and being able to maintain the sharp > >> boundaries while up scaling. > > > Is this something that needs to be specified, or is it just a > > qualty-of-implementation issue? > > It does need to be specified (and already is, though apparently it > needs to be made clearer). interpolation colourspace lets you choose > between performing calculations in faster but inaccurate sRGB or in > linear (not gamma companded) sRGB. > Can you tell me where it is specified? color-interpolation doesn't apply and color-rendering doesn't mention gamma > Not specifying it makes it untestable and permits implementations to > produce conformant, but visually very distinct, renderings of the > same content. > Yes, we don't want inconsistent rendering. If possible, we would also like an option to turn it off as Adobe's vector applications always do downsampling in the same colorspace as the document.
Received on Thursday, 17 April 2014 15:33:29 UTC