Re: wherefore CGM?

Inigo Lopez (
Mon, 09 Dec 1996 14:30:22 +0100

Subject: Re: wherefore CGM? 
In-reply-to: <> 
Date: Mon, 09 Dec 1996 14:30:22 +0100
Message-ID: <>
From: Inigo Lopez <>

En fecha/On Sat, 7 Dec 1996 19:31:51 -0800  "David Perrell" expuso/wrote:=

> > Think web! The _user agent_ knows all it needs to know. What the
> > display is and what the graphics format is.
> =

> Does the user agent know the pixel density the image was created for?
> That would be the best basis for determining whether or not to resize.
> PNG doesn't appear to have chunks for this info, and I don't think it's=

> in GIF or JPEG either. =

Yes, the user agent should know the pixel density of the image.

PNG *does* have a chunk named pHYs where you specify the image physical =

dimensions. Of course JPEG also stores information about density. I don't=
 know =

about GIF, but I hate it anyway and its days are over.

All images should have density information. The web browser should know t=
he =

density of the intended display device (monitor, printer, etc.) and optim=
ize =

the image for output at that density. This is the way to go, no comment.

I=F1igo L=F3pez