[comp.sys.mac] 24 Bit RGB to 8 Bit on Macintosh

pepke@loligo.cc.fsu.edu (Eric Pepke) (09/09/89)

I am finishing up an application on the Macintosh to convert 24 bit RGB 
image files to 8 bit pictures with color look up tables using a variant
of Paul Heckbert's algorithm.  

Currently, it can read .PIC files produced by the MTV ray tracer, display
them on the screen, and save them in a format understood by NCSA Image.
It can also do some animation and copy individual pictures to the
clipboard.

This is enough for my needs, but I would like to modify it to accept and 
produce other kinds of files as well; however, I need some help on which
formats to support.  If you have a use for this application, and you have 
a file format that you would like it to support, please send a complete and
precise definition of the format and a small binhexed sample to me at the 
INTERNET address below.  I can use formats for

1) Single 24 bit RGB images
2) Sequences of 24 bit RGB images
3) Color look up tables
4) Single 8 bit images 
5) Sequences of 8 bit images

I am particularly interested in the formats of files produced by renderers
in addition to the MTV ray tracer and in the formats of color image editors
such as PixelPaint.  If there is reason to do so, I can even support output
to files with fewer than 8 bits per pixel.

So, please send in those formats!  When the application is done, it will be 
distributed for free.

Eric Pepke                                     INTERNET: pepke@gw.scri.fsu.edu
Supercomputer Computations Research Institute  MFENET:   pepke@fsu
Florida State University                       SPAN:     scri::pepke
Tallahassee, FL 32306-4052                     BITNET:   pepke@fsu

Disclaimer: My employers seldom even LISTEN to my opinions.
Meta-disclaimer: Any society that needs disclaimers has too many lawyers.

recerik@alliant.uni-c.dk (Erik Bertelsen) (09/10/89)

In article <176@vsserv.scri.fsu.edu> pepke@loligo.cc.fsu.edu (Eric Pepke) writes:


   This is enough for my needs, but I would like to modify it to accept and 
   produce other kinds of files as well; however, I need some help on which
   formats to support.  If you have a use for this application, and you have 
   a file format that you would like it to support, please send a complete and
   precise definition of the format and a small binhexed sample to me at the 
   INTERNET address below.  I can use formats for

Besides various product specific formats it would be nice if your application
could interpret the PICT-file formats used by Apple and other companies'
products. These products use a few new PICT opcodes besides those in IM-V for
direct RGB-values in each pixel instead of using colour lookup tables.

Lately I have seen several requests for information from Apple on the new
32-bit QD supported PICT formats, but I haven't seen any answers indicating
how to get this information.

Regards -
Erik Bertelsen
UNI-C, The Danish Computing Centre for Research and Education.