- From: David Dorward <david@dorward.me.uk>
- Date: Sun, 17 Sep 2006 12:28:48 +0100
- To: www-style@w3.org
On Sun, Sep 17, 2006 at 01:07:32PM +0200, Axel Dahmen wrote:
> What is rendered on screen always varies depending on the screen
> resolution. Units like "pt" are never displayed in their correct
> sizes.
Most systems are not calibrated correctly so the system can't convert
points to pixels accurately (there may also be browser bugs
involved). I don't see how any change to the CSS specification could
work around this problem.
> Similar for printing: "px" unit rules are never printed in the
> printer's resolution.
They shouldn't be:
Pixel units are relative to the resolution of the viewing device,
i.e., most often a computer display. If the pixel density of the
output device is very different from that of a typical computer
display, the user agent should rescale pixel values.
-- http://www.w3.org/TR/CSS2/syndata.html#value-def-length
> The new "scaling" rule should only allow
> * percentage values
> * a factor to set a fix scaling, using length units:
> something like
> "300pt" => 300 pixels equal one Point
> "500cm" => 500 pixels equal one Centimeter
This seems to be moving responsibility for defining the DPI of the
system from the system administrator (who has a chance of configuring
it correctly) to the document author (who, in the case of the WWW at
least, hasn't a hope of doing so).
--
David Dorward http://dorward.me.uk
Received on Sunday, 17 September 2006 11:28:58 UTC