2009.04.26 17:22 "[Tiff] Packbits worst case encoded length", by Simon Berger

2009.04.29 14:28 "Re: [Tiff] Packbits worst case encoded length", by Toby Thain

2009.04.30 07:41 "Re: [Tiff] Packbits worst case encoded length", by Albert Cahalan

2009.04.30 13:58 "Re: [Tiff] Packbits worst case encoded length", by Toby Thain
 2009.04.30 19:12 "Re: [Tiff] Packbits worst case encoded length", by Albert Cahalan

2009.04.30 13:58 "Re: [Tiff] Packbits worst case encoded length", by Toby Thain

2009.04.30 07:41 "Re: [Tiff] Packbits worst case encoded length", by Albert Cahalan
 2009.04.29 18:07 "Re: [Tiff] Packbits worst case encoded length", by Simon Berger
 2009.05.05 19:13 "Re: [Tiff] Packbits worst case encoded length", by Albert Cahalan
2009.04.29 19:43 "Re: [Tiff] Packbits worst case encoded length", by Simon Berger
I think your formula was correct, for a besteffort compressor.
Those answers really aren't helpful.
 I know that it has to be correct because it is from the specification of the packbits algorithm
 I pointed out that I need to get a presumption of the libtiff implementation of packbits.
The reason for point 2 is a lossless recompression of Tiff files I do. You can read it here:
http://encode.ru/forum/showthread.php?t=332