RE: OT / OFF header info

Hi David,

One reason I brought it up is because there is an open ballot for the ISO OFF document, and we wanted to suggest certain changes to the definition of the flag this can definitely be mentioned in ballot comments. I can ask MS folks if they don't mind changing the definition for this bit to make it more generic and not tied to MTX explicitly, but my gut feeling is that this should be a simple and non-controversial change since the meaning of the bit will not be affected.

Thank you,
Vlad


-----Original Message-----
From: David Kuettel [mailto:kuettel@google.com] 
Sent: Monday, April 28, 2014 3:57 PM
To: Levantovsky, Vladimir
Cc: w3c-webfonts-wg (public-webfonts-wg@w3.org)
Subject: Re: OT / OFF header info

Interesting.

Given that the documentation for the bit, explicitly refers to MicroType (MTX) compression, would it be confusing to directly reuse the bit for WOFF 2.0?

To explore further, do you think Microsoft would be open to refining the text to make it more general?

>From the documentation (http://www.microsoft.com/typography/otspec/head.htm):

"Bit 11: Font data is 'lossless,' as a result of having been compressed and decompressed with the Agfa MicroType Express engine."

On Mon, Apr 28, 2014 at 11:20 AM, Levantovsky, Vladimir <Vladimir.Levantovsky@monotype.com> wrote:
> Folks,
>
>
>
> I wanted to bring to your attention (and up for discussion) the 
> following
> consideration:
>
>
>
> The OpenType / OFF font header table
> (http://www.microsoft.com/typography/otspec/head.htm) has 16-bit flags 
> field where bit 11 is assigned to signal if a font has been subjected 
> to MTX transform. I believe that the original purpose of allocating 
> and setting the flag was to indicate that the font has been 
> transformed and, although it is functionally equivalent to the 
> original font, its binary representation differs from the original (hence invalid or absent DSIG table, etc.).
>
>
>
> I believe that the same would be true for WOFF2 transform, so it may 
> be appropriate to include a reference (e.g. in section 4.4 of the 
> WOFF2 spec) and suggest that the decoder should have this bit 11 of 
> the 'head' table flags set when the font is decompressed. Doing this 
> would be logical (and IMO consistent with the original intent of the 
> OpenType spec) but I really don't know if there are any engines out 
> there that would pay attention to this flag. It may not make any 
> difference in the end but rather be one extra bit of info that someone (anyone?) might find useful.
>
>
>
> Thought?
>
> Thank you,
>
> Vlad
>
>

Received on Monday, 28 April 2014 20:24:53 UTC