pnminterp - scale up a PBM/PGM/PPM smoothly, by interpolating between pixels.
Copyright (C) 1998 Russell Marks.

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or (at
your option) any later version.

This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
General Public License for more details.


Description
-----------

`pnminterp' scales up a PBM/PGM/PPM file by an integer ratio - so
`pnminterp 2' gives 2x2 versions of the input's pixels, `pnminterp 3'
gives 3x3 ones, etc. The advantage of using pnminterp rather than
pnmscale/pnmenlarge is that pnminterp interpolates between the input
pixels in the output image, producing a much less ugly result than
those do.

Those familiar with zgv's scaling-with-interpolation mode may
recognise the effect. Indeed, most of the code is derived from zgv.

There's also a shell script `pnminterp-gen' which lets you scale
smoothly by any ratio (it works by using pnminterp/pnmfile/pnmscale).

More details are in the man pages.


Contacting me
-------------

You can email me at rus@forfree.at but since I'm not on the net, mail
received there is just posted to me at regular intervals by a friend
(and similarly I post responses back to be emailed). It could take as
long as six weeks for you to get a response - if that's a problem,
then you could write to me directly instead (more hassle, but usually
quicker).

You can write to me at:
		Russell Marks,
		3 Rapley Close,
		Camberley,
		Surrey,
		GU15 4ER,
		United Kingdom.


Share and enjoy! 

-Rus.
