
/*  %Z%%M% %I% %E%
 *
 *  Popi v3.4.0
 *
 *  Popi was originally written by Gerard J. Holzmann - AT&T Bell Labs.
 *  This version is based on the code in his Prentice Hall book,
 *  "Beyond Photography - the digital darkroom," ISBN 0-13-074410-7,
 *  which is copyright (c) 1988 by Bell Telephone Laboratories, Inc.
 *
 *  Permission is given to distribute these extensions, as long as these
 *  introductory messages are not removed, and no monies are exchanged.
 *
 *  No responsibility is taken for any errors or inaccuracies inherent
 *  either to the comments or the code of this program, but if reported
 *  (see README file) then an attempt will be made to fix them.
 */

Popi  -  README  -  February 2002.

---------------------------------------------------------------------------
CONTENTS:

1. What is Popi?
2. Getting started.
3. Popi history.
4. Popi image format.
5. Acknowledgements.
---------------------------------------------------------------------------

1. What is Popi?
----------------

Popi is a program that allows arbitrary transformations to be interactively
applied to digital images. It is based on the program described in "Beyond
Photography - The Digital Darkroom" by Gerald J. Holzmann.
See the manual page for details of all the options available to you, plus
examples of how to use them.

The graphical interface to popi can be very simple, or enhanced for a
particular graphics environment.

  IMPORTANT NOTE: 
  ---------------
  Only the X11 graphics driver has been tested with this release.

  The following graphics drivers worked correctly in the previous release 
  of this software. They will mostly all need to be "ported" again. You
  can find the current source code in the "drivers" directory.

  Graphical device drivers are currently included for:

	Amiga
	    Works with Lattice C 5.04, but you'ld better have at
	    least 2M of memory, or restrict yourself to small (128by128)
	    images.
	Apollo
	Atari terminal
	Hewlett Packard
	Kermit terminal
	MGR
        NeXT
            Tested on a NeXT-Dimension system, works with NeXTstep 2.1.
            It uses a screen-depth of 32 bits and leaves dithering to
            the Display-Postscript system. It doesn't support :monochrome.
	PC
	    Works with Turbo C, Microsoft C (including Quick C)
	    and Mix Software's Power C. There is support for
	    the common graphics cards (CGA, EGA, VGA, HGC) and
	    additionally, the Turbo C graphics library routines
	    can be used for non-standard cards if you have
	    the appropriate .BGI file.
	X11
            Works with X11R4 and X11R5.
	XView
            Needs the XView toolkit source distribution or Open Windows v1.0.
	null
	    For those with no graphics screen, this enables
	    you to just use one of the printer options.

Output is available for:
	PostScript
	Epson printers.

The latest version of popi is available via anonymous ftp from 

    http://java.sun.com/people/richb


2. Getting started.
-------------------

See the file 'INSTALL'

The manual pages also describe how to use popi in detail, and include several
examples.

There is a TODO file included which lists current bugs, and the
enhancements that will be added in the future.


3. Popi history.
----------------

This program was first released to aus.sources in July 1989 in conjunction
with a competition held prior to this year's Australian Unix User's Group
Conference and Exhibition. The best transformation of Dennis Ritchie's face
(as judged by Dennis) was put on T-shirts that were given to each conference
delegate. Bug-fixes, improvements and new drivers were garnered. A number of
vendors had popi running at the exhibition.


4. Popi Image format.
---------------------

Popi uses the portable graymap file format for the grayscale images, and
the portable pixmap file format for it's color images. These image formats
are an integral part of the PBMPLUS extended portable bitmap toolkit
distributed by Jef Poskanzer.

PBMPLUS provides comprehensive format conversion and image manipulation
capabilities. The latest version is always available via anonymous FTP as
export.lcs.mit.edu:contrib/pbmplus*.tar.Z and ftp.ee.lbl.gov:pbmplus*.tar.Z.

These routines (which have been isolated into libpbm.c and libpbm.h) are:

Copyright (C) 1989 by Jef Poskanzer.

Permission to use, copy, modify, and distribute this software and its
documentation for any purpose and without fee is hereby granted, provided
that the above copyright notice appear in all copies and that both that
copyright notice and this permission notice appear in supporting
documentation.  This software is provided "as is" without express or
implied warranty.

If you have some image files in the old popi image format, they can be
converted to pgm format by using the popitopgm filter. See the popi manual
pages for more details.

This version of popi uses error diffusion floyd-steinberg dithering for
displaying the images on monochrome screens. The routines to do this were
taken from the xloadimage package.

These routines (which have been isolated into dither.c) are:

Copyright 1989, 1990 Kirk L. Johnson
Copyright 1989, 1990 Jim Frost and Steve Losen.

Permission to use, copy, modify, distribute, and sell this
software and its documentation for any purpose is hereby granted
without fee, provided that the above copyright notice appear in
all copies and that both that copyright notice and this
permission notice appear in supporting documentation. The
author makes no representations about the suitability of this
software for any purpose. It is provided "as is" without express
or implied warranty.

THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS,
IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, INDIRECT
OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

5. Acknowledgements.
--------------------

See the AUTHORS file.

----------------------------------------------------------------------------

Suggestions for further improvement would be most welcome, plus bug reports
and comments.

Rich Burridge,          rich.burridge@Sun.COM
