Re: [Devel] 'tension' in splines, Hermite Splines

[Vadim Plessky]

On Saturday 14 September 2002 5:04 am, Werner LEMBERG wrote:
|  George will be away for a month, so he asked me to forward this mail.
|
|      Werner

Quote George Williams:
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At 08:38 PM 9/11/2002 +0400, Vadim wrote:
>IkarusM displays all "on-curve" points, treating the curves
>   as Hermite splines, which it converts to Beziers when making Type1 or

According to Peter Karow's book "Digital Formats for Typefaces" page 109 
(describing how Ikarus interpolates between two curve points):
         We do not take the spline function to display the closed curve but
         rather, between any two digitized points, we determine two segments
         of circles.
ie. not hermite splines. A more complete description of this circular 
interpolation (along with code) is given in Appendix W of that book, pages 
357-374.

This is the book URW++ referred me to (last month) when I asked them about 
Ikarus's font format, so I presume it is as accurate as anything available.
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Google pointed me to this URL:
http://members.aol.com/willadams/techref.htm

Which has references to *two different books*, both published in 1994:
***
1. Karow, Peter, Digital Typefaces: Descriptions and Formats. Trans. Bill 
Horton. Berlin: Springer-Verlag, 1994. ISBN 0-387-56509-4. 

Discussion of the professional typeface creation package Ikarus and how it 
relates to more current formats and methods of electronic typeface production 
and creation and output. Second edition of Digital Formats for Typefaces. 
Karow, Peter. Font Technology: Descriptions and Tools. Trans. Bill Horton. 
Berlin: Springer-Verlag, 1994. ISBN 0-387-57223-6. Continuation of the above 
book, examining the methods and techniques relating to the manufacture of 
type, as well as a discussion of font quality and hinting. 

2. Karow, Peter. Font Technology: Descriptions and Tools. Trans. Bill Horton. 
Berlin: Springer-Verlag, 1994. ISBN 0-387-57223-6. 

Continuation of the above book, examining the methods and techniques relating 
to the manufacture of type, as well as a discussion of font quality and 
hinting. 

-------------------------------------
In fact, I has second book in Russian translation (published here in 2001), 
and I was keeping in mind materials from that book when speaking about IKARUS 
& different hinting models.
I think George has first one.
Is there someone who has both books? ;-)

Some statements by Peter Karow are really questionable (like: TrueType has no 
future, as only 70 fonts available in TrueType format, comparing to 1000 
fonts avalable in PostScript format; or that all scanning process should be 
done by hand, via tablet), but on the other hand, he provides quite valuable 
estimation of hinting complexity and determining quality of typefaces.

BTW: does someone know wether those books are available in PDF format, or 
online in HTML format, somewhere?

-- 

Vadim Plessky
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