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<DIV dir=ltr align=left><SPAN class=148553018-05092008><FONT face=Arial
color=#0000ff size=2>Dear mpsuzuki-san,</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=148553018-05092008><FONT face=Arial
color=#0000ff size=2></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=148553018-05092008><FONT face=Arial
color=#0000ff size=2>Thank you very much for your
valuable comments.</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=148553018-05092008><FONT face=Arial
color=#0000ff size=2></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=148553018-05092008><FONT face=Arial
color=#0000ff size=2>I will edit the header title for 'kern' table as you
suggested.</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=148553018-05092008><FONT face=Arial
color=#0000ff size=2></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=148553018-05092008><FONT face=Arial
color=#0000ff size=2>The "Recommendation" section (I believe this is what you
were referring to as "cross-platform notes") has not been dropped. The
whole section is in the text of the ISO/IEC 14496-22, clause 6 "Recommendations"
(you can find comments specific to 'kern' table on page 365 of the current draft
FCD, and comments on 'cmap' table on page 364).</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=148553018-05092008><FONT face=Arial
color=#0000ff size=2></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=148553018-05092008><FONT face=Arial
color=#0000ff size=2>As far as 'kern' table and subtable version numbers and
field definitions are concerned - the current text is identical to original text
of OpenType specification 1.4 and 1.5. I f you believe it would be
beneficial to modify / update the field descriptions - we would need to discuss
and approve these changes as part of the established ISO ballot process. AHG can
not make these decision on its own, without having it discussed and approved by
the SC29/WG11. I would encourage you to submit your comments and proposals
as FCD ballot National Body comments.</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=148553018-05092008><FONT face=Arial
color=#0000ff size=2></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=148553018-05092008><FONT face=Arial
color=#0000ff size=2>Thank you and best regards,</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=148553018-05092008><FONT face=Arial
color=#0000ff size=2>Vladimir</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=148553018-05092008><FONT face=Arial
color=#0000ff size=2></FONT></SPAN> </DIV><BR>
<BLOCKQUOTE
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<DIV class=OutlookMessageHeader lang=en-us dir=ltr align=left>
<HR tabIndex=-1>
<FONT face=Tahoma size=2><B>From:</B> mpeg-OTspec@yahoogroups.com
[mailto:mpeg-OTspec@yahoogroups.com] <B>On Behalf Of
</B>mpsuzuki@hiroshima-u.ac.jp<BR><B>Sent:</B> Friday, September 05, 2008 2:23
PM<BR><B>To:</B> Levantovsky, Vladimir<BR><B>Cc:</B> mihill@microsoft.com;
mpeg-OTspec@yahoogroups.com<BR><B>Subject:</B> Re: [mpeg-OTspec] AHG on Open
Font Format kick-off<BR></FONT><BR></DIV>
<DIV></DIV>
<DIV id=ygrp-text>
<P>Dear Vladimir Levantovsky,<BR><BR>I'm quite sorry for writing the comment
on 2nd FCD in the<BR>near of deadline.<BR><BR>Recently I've discussed about
the implementation of "kern"<BR>table with Joshua Hadley, in OpenType mailing
list, and<BR>read the corresponding parts of existing specifications.<BR>Then,
I find that I should comment a few points.<BR><BR>Editiorial
comment<BR>------------<WBR>------<BR><BR>In Contents page iv, the most titles
of the sections for<BR>OFF tables are in the style like "cmap - Character to
Glyph<BR>Index Mapping Table". But the title of the section for<BR>kern table
is just "Kerning". I think "kern - Kerning"<BR>is compatible with other
titles, and compatible with<BR>OpenType spec (<A
href="http://www.microsoft.com/typography/otspec/kern.htm">http://www.microsof<WBR>t.com/typography<WBR>/otspec/kern.<WBR>htm</A>)<BR><BR>non-Editiorial
comment (maybe)<BR>------------<WBR>---------<WBR>---------<BR><BR>Although
ISO/IEC 14496-22 doesn't mention about how to design<BR>a cross-platform kern
table, the existing specifications of<BR>Apple TrueType GX, Microsoft
TrueType, and OpenType note<BR>about how to make a cross-platform kern table.
Yet I've not<BR>tracked the reason why the cross-platform notes is
dropped<BR>in ISO/IEC 14496-22.<BR><BR>If ISO/IEC JTC1/SC29/WG11 experts
discussed and concluded<BR>as it should be removed due to unavoidable
incompatibilities,<BR>the discussion is worthful, I wish it should be
commented<BR>in ISO/IEC 14496-22 (even if it's out of main
sections).<BR><BR>In addition, there is an important note for kern table
in<BR>the recommendation: Microsoft Windows uses only the first<BR>subtable in
format 0, for horizontal/no cross-stream/<WBR>no<BR>override. I wish if it's
so important and should be moved<BR>to or repeated in the main section for
kerning table.<BR>It is possible for a careful reader to recognize that<BR>the
subtable format 2 is not supported by Windows nor OS/2,<BR>but it is difficult
to recognize that multiple subtable<BR>is not supported by Windows.<BR><BR>#
In the case of cmap table, the information "how to<BR># implement cmap table
including UCS-4 characters" is<BR># written in the subsection for cmap
subtable format 12<BR># and repeated in the recommendation.<BR><BR>Also, a few
definitions of the elements are slightly unclear.<BR><BR>"version" element in
the head of kern table:<BR>This element is described as "starts at 0".<BR>At
present, there's no description about the<BR>number of version for "kern"
table, I think<BR>"Set to 0" is better. Why? Although it is out<BR>of the
scope of OpenType specification, Microsoft<BR>platform seems to ignore this
element at all and<BR>Apple platform seems to distinguish original<BR>16bit
kern versus 32bit TrueType GX kern.<BR>To disambiguify, giving only version 0
is better.<BR>I wish if version 1 is described as reserved<BR>(as kern
subtable format number 1 and 3 are<BR>described as "reserved for future
use").<BR><BR>"version" element in the head of kern sub table:<BR>This element
is described as "Kern subtable<BR>version number". Although it seems that
most<BR>TrueType fonts set this element to 0, Microsoft<BR>and Apple platforms
seem to ignore this element.<BR>If the neglect of this element is not
essential,<BR>I wish if the standard value is defined, or,<BR>described as
this is not used (or renamed as<BR>reserved).<BR><BR>In addition, I want to
hear the comment from Apple, if they<BR>are interested in the standardization
how to distinguish<BR>the coverage element in kern subtable. The bitwise
interpretation<BR>of the coverage element is incompatible between
Microsoft<BR>TrueType (and OpenType) and Apple TrueType. If any
restriction<BR>makes it possible to distinguish OpenType 16bit kern
from<BR>Apple TrueType 16bit kern, I wish if it's addded in future<BR>OpenType
specification.<BR><BR>It seems that current Mac OS X automatically detects
OpenType<BR>16bit kern and parses it in OpenType syntax, but sometimes<BR>the
detection is confused. I have a few commercial fonts<BR>designed for Microsoft
Windows: they are kerned in Windows but<BR>not kerned in Mac OS X.<BR><BR>When
I and Masatake Yamato (Red Hat) implemented a validator<BR>of kern table, we
took a heuristic algorithm in following:<BR><BR>step1:<BR>extract 4bit from
LSB of coverage element and<BR>interpret it as the subtable format as
Apple<BR>16bit kern.<BR><BR>step2:<BR>If the subtable format is 0 or 2 and
requires<BR>the state machine of TrueType GX, the subtable<BR>is recognized as
of Apple 16bit kern.<BR>If it is 1 or 3, TrueType GX state machine
is<BR>required, so the interpretation is assumed to<BR>be wrong - go to step
3.<BR><BR>step3:<BR>extract 8bit from MSB of coverage element and<BR>interpret
it as the subtable format as OpenType<BR>16bit kern.<BR><BR>This algorithm is
not perfect. For example, the coverage<BR>element for vertical format 0 in
Apple 16bit kern would<BR>be 0x8000. This is same with the most popular
coverage<BR>element in OpenType 16bit kern (horizontal format
0).<BR><BR>Regards,<BR>mpsuzuki<BR><BR>On Thu, 14 Aug 2008 16:29:21
-0400<BR>"Levantovsky, Vladimir" <<A
href="mailto:vladimir.levantovsky%40monotypeimaging.com">vladimir.levantovsk<WBR>y@monotypeimagin<WBR>g.com</A>>
wrote:<BR>>The new version of the draft has been uploaded to AHG files
storage and<BR>>can be downloaded using the following link:<BR>><A
href="http://groups.yahoo.com/group/mpeg-OTspec/files/20080814-w10068_14496-22">http://groups.<WBR>yahoo.com/<WBR>group/mpeg-<WBR>OTspec/files/<WBR>20080814-<WBR>w10068_14496-<WBR>22</A><BR>>_FCD_2nd-Ed.<WBR>zip<BR>><<A
href="http://groups.yahoo.com/group/mpeg-OTspec/files/20080814-w10068_14496-2">http://groups.<WBR>yahoo.com/<WBR>group/mpeg-<WBR>OTspec/files/<WBR>20080814-<WBR>w10068_14496-<WBR>2</A><BR>>2_FCD_2nd-Ed.<WBR>zip>
<BR>><BR>> <BR>>I will be on vacation Aug. 16-30 and will not have
access to email. I<BR>>would like to ask you to continue the review of the
FCD text in<BR>>preparation for our AHG meeting/teleconfere<WBR>nce on
September 8. I will<BR>>announce the detailed agenda for the call as soon
as I come back from<BR>>vacation.<BR>> <BR>>Thank
you,<BR>>Vladimir<BR></P></DIV><!--End group email --></BLOCKQUOTE></BODY></HTML>