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Re: [css3-images] Is the dppx unit needed?

From: Tab Atkins Jr. <jackalmage@gmail.com>
Date: Tue, 24 May 2011 10:34:55 -0700
Message-ID: <BANLkTimcoAgh9eCJ8uOTh8itiwmz3J6hPQ@mail.gmail.com>
To: Brad Kemper <brad.kemper@gmail.com>
Cc: Sylvain Galineau <sylvaing@microsoft.com>, www-style list <www-style@w3.org>
On Tue, May 24, 2011 at 10:32 AM, Brad Kemper <brad.kemper@gmail.com> wrote:
> On May 24, 2011, at 9:46 AM, "Tab Atkins Jr." <jackalmage@gmail.com> wrote:
>>> Pretty much. The weak use case was all I could think of. That being, if you want an integer number of image pixels per px (for sharper results), then it would be easier to say '2dppx' or '3dppx' than to multiply by 96 for dpi.
>>>
>>> In your image() function you have 'snap' to fulfill a similar (perhaps not identical) purpose.
>>
>> Basically the same purpose.  "300dpi snap" should resolve into 288dpi,
>> so you get an even 3 image pixels per CSS px.
>
> If I am reading it right, the snap is to device pixels, right? So it could be something different when printed to a laser printer. I think that is a good thing, and should be noted.

Yup, precisely, on a printer you'll generally get exactly 300dpi.  And
you're right, that should be explicitly noted.


> PS. You have a note about using a term, "pixel rounding". Perhaps you could say "fractional pixels" there instead. Or "rendering that simulates fractional pixels".

Hmm, kk.  I'll work on that line and see what comes out.

~TJ
Received on Tuesday, 24 May 2011 17:35:42 GMT

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