Re: Justification (was Re: Unicode Font Maker)

[Meor Ridzuan Meor Yahaya <meor dot ridzuan at gmail dot com>]

Tatweel is only the very basic method of justifying arabic text, which
in actual calligraphy, calligraphers seldom use it. Most of the time
they will use alternate glyph (such as a wide kaf), either to make it
wider or to compressed it more. Paul Nelson from Microsoft did
mentioned in Volt community (I asked the question) that MS approach is
to compressed the line as much as possible, then later to make it
wider using tatweel.

So, my earlier question is not just how a software should do the
justification, but rather on how the whole thing should be tackle.
>From Mr Milo brief description, I don't quite get how his appraoch
/technology handle it .

Basically, there are 2 component required for this:

1. Font itself. This should be designed by professional calligraphers,
implement by font technology expert (well, maybe we don't need an
expert level). The font should be able to provide all the necessary
glyph and information on how justification should be done (speficic to
the font, either how to enpand it or to compress it) Since I'm not an
expert in calligraphy, I don't know much on the exact techniques to
expand/compress text. just from my observation of the Quran Mushaf.

2. The rendering technology. The technology should be general/flexible
enough to take the full advantage of what a font has to provide (in
terms of justification), or if the font does not provide it, it must
be able to do basic justification technique by inserting
tatweel/spaces at appropriate places.

If we have these features, users doesn't have do anything when
encoding the text. It is in my opinion that the 2 should be seperated,
so that any calligraphers can design their own font with their own
preferences.

At the moment, Opentype does have JALT table, but I think it is not
sufficient because we don't have the options on how to compress the
text, only to expand (I think , because it does have only one table).
Plus, no software is known to take advange of it (not sure software
from Adobe)

I don't know much about Mr Milo ACE technology, but if he allows third
party font designers to design a font for his technology, I would be
interested to know.

Regards.

On 8/4/05, Mete Kural <metek at touchtonecorp dot com> wrote:
> Hello Gregg,
> 
> By <TATWEEL> you mean the Unicode codepoint 0640 Arabic Tatweel? Using 0640 Tatweel in Arabic text on a regular basis is a non-starter. Tatweel is a typographic feature, it shouldn't be encoded in raw text. But a rendering engine could perhaps make use of it by pre-processing raw encoded text and inserting tatweels where desired before sending it to be rendered. An encoder should not have to encode Tatweels on a regular basis in Arabic text.
> 
> Regards,
> Mete
> 
> ---------- Original Message ----------------------------------
> From: Gregg Reynolds <gar at arabink dot com>
> Reply-To: General Arabization Discussion <general at arabeyes dot org>
> Date:  Wed, 03 Aug 2005 11:02:03 -0500
> 
> >Thomas Milo wrote:
> >> Meor Ridzuan Meor Yahaya wrote:
> >>
> >>
> >>>Do you have ideas on arabic justification that you don't mind sharing
> >>>with us?
> >>
> >>
> >> Yes. Considering keshide or madd a justification aid does not do justice to
> >> the art of calligraphy or typesetting. Keshide is an esthric device, not a
> >> trick. It serves to change the general appearance of text, in other words,
> >> you use them or you don't. If used, in calligraphy and well-executed
> >> typesetting, keshide is bound to many contextual constraints, which, just
> >> like the ligature system, are not generally know among computer
> >> enthousiasts, with devastating consequences for the Islamic art of text
> >> composition.
> >>
> >> To sum it up: justification can very well be achieved by subtle variation in
> >> intra-word and inner-word spacing. Only as a last resort keshide should be
> >> used for justification.
> >>
> >
> >Here's my solution:  define <TATWEEL> to mean "this place is a candidate
> >for extension of the line, regardless of coloration", such that it takes
> >on color based on context.  E.g. <k><tatweel><t><b> means the positive
> >(inked) space between <k> and <t> (i.e. the tiestroke) may be extended.
> >  <d><tatweel><w><r> means the negative space (whitespace) between <d>
> >and <w> may be extended.  The relative extent of such stretching would
> >be set by typesetting policy in the software.  Then there are four
> >groups of extension candidates: ordinary inter-word negative space,
> >explicitly specified stretch candidates (using tatweel), and ordinary
> >intra-word positive (black) and negative (white) space.  It's up to the
> >composition system to set policy regarding how extra space is
> >distributed among these categories.  This is pretty much how the TeX
> >justification algorithm works.
> >
> >-gregg
> >
> >
> 
> --
> Mete Kural
> Touchtone Corporation
> 714-755-2810
> --
> 
> 
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