Welcome to CUPS-PNG v2

 CONTENTS:

  0. introduction
  1. building CUPS-PNG
  2. setting up the PDF queue with CUPS
  3. note for MacOSX
  4. contact


0. introduction
---------------

   Note that this whole project was blatantly ripped from CUPS-PDF and
   hacked to generate PNG files instead of PDF files.  Perhaps the two
   should be merged someday with just a printer option to say what kind of
   file to generate (but then I'd have to figure out how to provide that
   option). This readme was generated by crossing out PDF with a crayon
   and writing in PNG :-).

1. building CUPS-PNG
--------------------

   Edit src/cups-png.h if you do not like /etc/cups/cups-png.conf as name 
   for the configuration file.
   To compile CUPS-PNG, invoke gcc in the src/ directory:

   gcc -O9 -s -o cups-png cups-png.c

   To install the binary, simply copy cups-png to the backend directory
   of CUPS (usually /usr/lib/cups/backend).

   Now copy extra/cups-png.conf to /etc/cups (or whatever location you
   selected in cups-png.h above). Here you can set all properties of 
   CUPS-PNG at runtime without the need for restarting any services.
   (The defaults should work fine on most systems.)

   In case you want to use the color PostScript driver that comes with
   CUPS-PNG go to the extra/ subdirectory and copy 
   PostscriptColor.ppd.gz to your cups model directory (usually 
   /usr/share/cups/model). 
   There are currently two releases of this driver available: rev3b and
   rev4 - the latter one will use the full pagesize, rev3b will stay 
   within the usual printer's margins.


2. setting up the PDF queue with CUPS
-------------------------------------

   Important notes:
   ================
   *CUPS-PNG requires root privileges since it has to modify file ownerships. 
    In recent distributions the "RunAsUser" option in cupsd.conf is set to 
    "Yes" which removes these privileges. Please make sure to set 
    "RunAsUser No" if you want to use CUPS-PNG.
    *** Starting with version 1.2.0 CUPS implements the "RunAsOption" no 
        longer. In order to ensure CUPS-PNG is running with the required root 
        privileges you have to make 'root' the owner of the cups-png backend 
        and set the file permissions of the backend to 0700 (root only).
   *make sure if any of CUPS-PNG's working directories (e.g. output) is a 
    NFS mounted volume it is mounted without root_squash!
   *CUPS-PNG is known to fail if the gs (GhostScript) binary on a system is 
    compressed by upx (Ultimate Packer for eXecutables).
   *if you are using SELinux make sure it does not interfere with CUPS-PNG
    (you can disable SELinux for CUPS by "setsebool -P cupsd_disable_trans 1"
     or have a look at contrib/SELinux-HOWTO to make it work)

   Now after restarting CUPS you will be able to choose "Virtual Printer (PDF
   Printer)" when setting up a new printer in CUPS.
   To set up a queue for other UNIX clients you should select Postscript as
   vendor and the Color Printer as model for your new printer; queues that get
   their input from samba or netatalk (i.e. Windows, OS/2 or MacOS) can be set
   up as raw queues. On the Windows, OS/2 or MacOS system choose a color
   postscript driver for that network printer (the drivers for Minolta Page
   Works or HP DesignJet printers do a good job).
   Hint: If you want to create grayscale PDFs you just have to choose a
   grayscale printer driver, i.e. the postscript.ppd that comes with CUPS on
   the Linux side or a b/w laser printer (e.g. a HP LaserJet) on the Windows
   side. On the Linux side be aware that the postscript.ppd will not
   re-process data that is already supplied in Postscript format, i.e. a color
   Postscript will keep it's colors.

   Once you print to the new device the output directory selected in
   cups-png.conf (defaults to /var/spool/cups-png) will be created and all
   converted PDF files will be placed in subdirectories named after the owner
   of the print job. In case the owner cannot be identified (i.e. does not
   exist on the server) the output is placed in the directory for anonymous
   operation (if not disabled in cups-png.conf - defaults to 
   /var/spool/cups-png/ANONYMOUS/).
   Furthermore if logging is enabled the logfile will be placed by default in
   /var/log/cups.

   The file "PostscriptColor.ppd.gz" is a modified version of the
   "Postscript.ppd.gz" that comes with CUPS 1.1.15 that is able to handle
   color output.

   You should have a look at the contrib/ directory in this bundle which
   contains several additions to CUPS-PNG which enhance functionality or 
   supports the setup of CUPS-PNG on different platforms.


3. note for MacOSX
------------------

   Since MacOSX' AFPL GhostScript does not support the way of PDF generation 
   used by CUPS-PNG you will have to use pstopdf instead. For this the
   settings of GhostScript, GSCall and PDFVer in cups-png.conf have to be
   changed accordingly. The values are documented in cups-png.conf .


4. contact
----------
   Tom Horsley
   tomhorsley@adelphia.net

   Based on original cups-pdf software by:

   Volker Christian Behr
   vrbehr@cip.physik.uni-wuerzburg.de
   http://cip.physik.uni-wuerzburg.de/~vrbehr/cups-pdf

