GBM Legal Stuff

Public domain declaration

Andy Key wrote most of this code in his own time on his own equipment. He used public non-confidential information to do so. He placed all this code into the public domain.

I (Heiko Nitzsche) have added code under the same conditions and place all my donated code into the public domain. This does not apply to the used JPEG, PNG and TIFF helper libraries. These libraries have their own license.

Feel free to do whatever you like with it.

No copyright / no royalties / no guarantees / no problem.
Caveat Emptor!

Anyone offering ideas/code must be happy with the above.


JPEG support

This section is applicable if you are using GBM with JPEG support.

The Independent JPEG Group JPEGLIB version 6a/6b may be used provided they are credited, (which I do so here).
This software is based in part on the work of the Independent JPEG Group.

Martin Lisowski has donated gbmjpg.c to GBM and it is just as public domain as the rest of GBM.

Compu$erve GIF Tax

Both Unisys and IBM (and others) have various patents pertaining to the LZW algorithm used in GIF and LZW compressed TIFF files.

For many years Unisys have only licensed their LZW technology in hardware implementations (typically Modems). Now Unisys (through Compu$erve) are looking to license the use of LZW in software applications, such as GIF and TIFF. This is the infamous 'Compu$erve GIF Tax'.

Unisys have stated (in news postings) that non-commercial software need not be licensed.
Assuming this to be true, GBM will continue to support GIF and LZW compressed TIFF.

It is anticipated that this move will mean the death of LZW in image files, and that the Net will develop a replacement based on LZSS, LZ77, LZHUF, Yabba or other (hopefully) non-patented technology. The PNG format is already available as a possible replacement.

If and when this occurs, there is a good chance GBM will support it.

On 20th June 2003, US Patent 4,558,302 expired. This is the patent that describes the use of LZW in GIF files. Therefore, from now on, authors of commercial programs should no longer need to pay Compu$erve / UNISYS to use GIF.

PNG support

This section is applicable if you are using GBM with PNG support.

The Open Source libraries Libpng and Zlib may be used provided they are credited, (which I do so here).
This software is based in part on them.

I (Heiko Nitzsche) have donated gbmpng.c and gbmmap.c to GBM and they are just as public domain as the rest of GBM.

TIFF support

This section is applicable if you are using GBM with TIF support.

The Open Source libraries Libtiff and Zlib may be used provided they are credited, (which I do so here).
This software is based in part on them.

I (Heiko Nitzsche) have donated gbmmap.c and a replacement gbmtif.c to GBM and they are just as public domain as the rest of GBM.

PPM support

This section is applicable if you are using GBM with PPM support.

I (Heiko Nitzsche) have donated gbmmap.c and a replacement gbmppm.c to GBM and they are just as public domain as the rest of GBM.