[comp.fonts] Scaling Transformation on Bitmap Characters.

doug@eris.berkeley.edu (Doug Merritt) (12/01/90)

In article <1990Nov5.022837.15506@ucselx.sdsu.edu> brian@ucselx.sdsu.edu (Brian Ho) writes:
>Hello out-there,
>  I am some problems which you may give me a hand.  I am trying to scale
>  some bitmap images, those images are characters (e.g. A B a b 1 2 ..etc)

This is a member of a well known and very hard set of related problems,
which are still generally considered unsolved in the general theoretical case.

However, John D. Hobby has recently published some extremely sharp results
in this area; although this is not going to be the last word in the subject,
it *is* brilliant landmark research. See "Generating Automatically Tuned
Bitmaps from Outlines", AT&T Bell Laboratories Computing Science Technical
Report No. 148. It will also be published in a journal, although which one
and when will not be announced until acceptance, of course.

The basic idea seems to be selecting a number of scaling error
criteria such as bending distortion, stretching distortion, etc,
and doing a least squares fit to minimize error. The paper is quite
analytical, not a cookbook, and source code is not available, at least
not right now.

This paper doesn't seem to be at all well known yet; perhaps I'm letting
the cat out of the bag? :-)
	Doug
	Doug Merritt		doug@eris.berkeley.edu (ucbvax!eris!doug)
			or	uunet.uu.net!crossck!dougm