[whatwg] Blurry lines in 2D Canvas (and SVG)

[Rik Cabanier]

All,

we've noticed that if you draw lines in canvas or SVG, they always end up
blurry.
For instance see this fiddle: http://jsfiddle.net/V92Gn/128/

This happens because you offset 1 pixel and then draw a half pixel stroke
on each side. Since it covers only half the pixel, the color gets mapped to
50% gray.
You can work around this by doing an extra offset of half the
devicepixelratio, but ideally this should never happen.

Is this behavior specified somewhere?
Is there a way to turn this off?