[whatwg] [canvas] imageRenderingQuality property
Oliver Hunt
oliver at apple.com
Mon Jun 2 12:25:32 PDT 2008
Um, could you actually give some kind of reasoning for these? I am
not aware of any significant performance issues in Canvas that cannot
be almost directly attributed to JavaScript itself rather than the
canvas.
--Oliver
On Jun 2, 2008, at 12:19 PM, Vladimir Vukicevic wrote:
>
> I'd like to propose adding an imageRenderingQuality property on the
> canvas 2D context to allow authors to choose speed vs. quality when
> rendering images (especially transformed ones). This is modeled on
> the SVG image-rendering property, at http://www.w3.org/TR/SVG/painting.html#ImageRenderingProperty
> :
>
> attribute string imageRenderingQuality;
>
> 'auto' (default): The user agent shall make appropriate tradeoffs to
> balance speed and quality, but quality shall be given more
> importance than speed.
>
> 'optimizeQuality': Emphasize quality over rendering speed.
>
> 'optimizeSpeed': Emphasize speed over rendering quality.
>
> No specific image sampling algorithm is specified for any of these
> properties, with the exception that, at a minimum, nearest-neighbour
> resampling should be used. One alternative is to specify 'best',
> 'good', 'fast', with "good" being the default, as opposed to the SVG
> names; I think those names are more descriptive, but there might be
> value in keeping the names consistent with SVG, especially if that
> property bubbles up into general CSS usage.
>
> - Vlad
>
More information about the whatwg
mailing list