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4. AP Font Library: The Current Status
Center for Global Communications (GLOCOM)
The AP Font Library is a set of computer fonts for languages in the Asia
Pacific region. It is based upon the AA Institute Fonts, which was developed
by the Institute for the Study of Languages and Cultures of Asia and Africa
(AA Institute), Tokyo University for Foreign Studies.
In October 1999, the Center for Global Communications (GLOCOM), International
University of Japan, was given permission from the AA institute to make
non-profit use of their computer font sets, and since then is undertaking
effort to make the font sets available in an outlined format. The languages
in the AA Institute Fonts includes Arabic, Traditional Mongol, Thai, Khmer,
Devanagari, Bengali, Tibetan, Laotian, Burma-Mhong, Tamil, Kannada, Malayalam,
and Telugu. Technical details of AA Font was given in our last year's report.
Of the font sets that were transferred to us, Khmer was chosen to be
the target of work in 2000, because we had close relationship with experts
in the development of Cambodian character fonts, who also are involved
in the standardisation of character code. The snapshot of our current work
is available as a TrueType font at the following url:
Our work is still underway and at this stage of development, the font is
not suitable for a practical purpose in any way, but we will keep refurbishing
it in the future.
How conversion works
As described in the 1999 report, AA Institute Font was designed for the
use of main frame computers, and it needs conversion in order to be used
on a PC platform. We started our conversion efforts with a group of Unix/Linux
tools that are freely available. However, those tools work best with glyph
data that has finer resolution than the AA Fonts, and it turned out that
the outlined glyphs resulted from conversion needed far more refinement
than was initially expected, which made it practically impossible to refine
each one of the glyph in the font.
In 2000, we made use of the following two commercially available products.
ScanFont automatically recognises the contour of an glyph shape and generates
an outlined glyph. FontLab helps to modify the shape of outlined glyphs
that are created by ScanFont or by other means. FontLab also add additional
information for the font.
ScanFont (Pyrus NA, Ltd.)
FontLab (Pyrus NA, Ltd.)
Problems to be addressed
The following issues arose during the conversion process.
The first one had been anticipated even before we started our work. Although
each glyph in AA Font is represented in a 96 by 96 matrix, the actual shape
of the glyph does not fill the entire matrix. Many of glyphs contain large
margin areas, top and bottom, and right and left, so that the actual shape
takes only a small portion of the matrix. Because the original data does
not contain enough information to reproduce outlined data, conversion ended
up with distorted contours and broken lines in many cases.
aesthetics of converted data
supplementation of additional information
assignment of glyphs in the code table
The second problem concerns how we supplement additional information
to the resulted font after conversion. AA Font has additional information
The image below shows how the logical width and horizontal position are
font code (given by AA Institute)
These items of additional information could be translated to our outlined
font in a technical sense, but they have not been reflected yet. It takes
a large amount of 'manual labour'. This remains one of the work items
for year 2001.
Assignment of glyphs to the code table raised another problem. Even
as of January 2001, there is no national standard for the coded character
set for Khmer. We assigned our glyphs to the Limon font, one of the most
widely accepted fonts in Cambodia. Limon sorts glyphs according to a proprietary
character code table. It is reported that standardisation work is underway
and we expect that we transplant our characters to the forth coming national
starndard in the near future.
Even with Limon, there are a couple of issues to be considered. There
exist glyphs that are contained in the AA Fonts, and not in Limon, and
ones that are not contained in the AA Fonts, but contained in Limon. Most
significant glyphs in AA Font correspond one-to-one to their counterparts
in Limon, but diacritics and precomposed glyphs often do not. We simply
excluded ones that do not match one-to-one this year.
Achievement in 2000
At the beginning of this year's work, we assumed that our primary work
was to extract outline data from the original bitmap and to apply aesthetic
adjustment. After a year long work, however, we recognised that additional
information, such as logical width and horizontal position plays much more
important role in appropriate processing by computer. In 2001, we will
focus more on additional information rather than adjusting the glyph shape
from a aesthetic point of view.
In terms of conversation of linguistic and cultural heritage, we believe
AA Font should be available in original bitmap as well. As part of this
year's achievment, we created tables of glyphs that are transferred
from AA Institute. The tables are accessible at the following web page.
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