Release notes for pnm2ppa-1.11 October 2002

- pnm2ppa-1.10 had problems with HP820C printers. Hopefully, these
  are fixed.   
- Also fixed: a memory leak affected all printer models  
  in certain circumstances: in high quality mode, if the last
  data on a page was in color, the final three print head passes
  were not printed, and the data was left in unfreed memory.
  (discovered using the "valgrind" memory-leak detector).
- compression of color data sent to the printer is now enabled.
  (only compression of black data was previously enabled).
  If it is suspected this is causing problems, it can be disabled by
  a new configuration file keyword "compression 0".
- Logging of normal informational messages to the system log is
  now turned off by default.  (They still go to stderr in "verbose" mode).
  Logging of information messages in the System Log can be re-enabled with
  a new configuration-file entry "log_info 1": this is only accepted
  from the default configuration file (/etc/pnm2ppa.conf). 
--------------------------------------------
Release notes for pnm2ppa-1.10 June 23 2002

- major rework of swath-cutting internals so black ink
  is never overprinted by color ink, and multipass color
  printing is bidirectional. Only tested on HP722C.
  Should have much better image quality now, we will have to see
  if the redesign has broken printing on HP820C, 1000C...
  Is anyone still using these PPA printers?
- new: a --dpi300 command line option for interpreting the
  input as 300dpi instead of 600dpi.  This may be useful for
  printing 300dpi pnm output directly from scanners.
-----------------------------------------------------  
Release notes for pnm2ppa-1.04 November 12 2000

- reduced memory footprint of calibrate_ppa from 36MB to 1.8MB
- fix bug in black shearing test pattern in calibrate_ppa
- fix bug in silent/vebose switches for  error messages.
-  repair the earlier 1.01 HP820 flashing light bug fix that got
  broken by the 600 dot yoffset shift in 1.03...
--------------------------------------------
Release Notes for pnm2ppa-1.02. 1.03 October 28 2000

- improved calibrate_ppa output, made configuration  easier
- change default offsets, etc. (add 600 to yoffset)
- added an automated lpd setup .

--------------------------------------------------
Release Notes for pnm2ppa-1.01 October 24, 2000
Fixed one more cause of "flashing light syndrome" on the
HP820C.  

Other changes:

Improved and functional calibration program, now called calibrate_ppa,
incorporating Bruno Alix's calibration pages from calibrateco.c
Moved the creation of "gamma.ppm" for color calibration from
pnm2ppa to calibrate_ppa.

All user input and syslog output was audited for security.
No incorrect user input is now echoed to the syslog; syslog
messages can be silenced with a new keyword "silent 1"
in  /etc/pnm2ppa.conf.   File paths entered as user input are
now handled carefully.

Gamma color enhancement values can now be given as decimals in the
configuration file.

The various inks can be switched off in the configuration file
(as an aid in  troubleshooting).

Release Notes for pnm2ppa-1.0  July 11, 2000
---------------------------------------------

This release is the 1.0 release of pnm2ppa.   It is fully functional
on all three PPA printer families, and has no known bugs. (Is "Flashing
LED syndrome a thing of the past?)

It can now handle all paper sizes compatible with the printer, and all pnm
formats.

The documentation is updated.

----

Remaining issues such as somewhat-visible horizontal swath boundaries on 
uniform dithered color backgrounds (such as in the ghostscript example 
tiger.ps)  cannot be resolved without major design changes, but this should 
not affect most uses of pnm2ppa. (see the TODO file).  
Such changes will require significant effort (by someone highly motivated) 
to be achieved. pnm2ppa is probably as good as it can get by tweaking its 
code with little bug fixes.
[FIXED IN v1.10]

Improvements in color correction techniques could still be achieved,
though (see docs/en/COLOR.txt).

Calibration and printer utility procedures (head cleaning codes, etc)
could also be added. (perhaps using the PUP utility?)
[NOW USE calibrate_ppa FOR SOME OF THESE FUNCTIONS]

Use of data compression of sweep data for color sweeps could also be
added without a major rewite, to perhaps speed up printing.
[FIXED IN v1.11]


The pnm2ppa team.
http://sourceforge.net/projects/pnm2ppa












