AWARE [SYSTEMS] Imaging expertise for the Delphi developer
AWare Systems, Imaging expertise for the Delphi developer, Home TIFF and LibTiff Mailing List Archive

LibTiff Mailing List

TIFF and LibTiff Mailing List Archive
August 2007

Previous Thread
Next Thread

Previous by Thread
Next by Thread

Previous by Date
Next by Date

Contact

The TIFF Mailing List Homepage
This list is run by Frank Warmerdam
Archive maintained by AWare Systems



Valid HTML 4.01!



Thread

2007.08.25 22:29 "24-bit samples in TIFF", by Bob Friesenhahn
2007.08.27 17:24 "Re: 24-bit samples in TIFF", by Chris Cox
2007.08.28 14:09 "Re: 24-bit samples in TIFF", by Toby Thain
2007.08.28 14:37 "Re: 24-bit samples in TIFF", by Frank Warmerdam
2007.08.28 14:57 "Re: 24-bit samples in TIFF", by Andrey Kiselev
2007.08.28 15:02 "Re: 24-bit samples in TIFF", by Bob Friesenhahn

2007.08.25 22:29 "24-bit samples in TIFF", by Bob Friesenhahn

Due to statements in Chris Cox's draft specification, it seems that 24 
bit values are now officially swapped to match the "host" endianness 
(a recent libtiff change).  However, there is no "host" endianness for 
24 bits for any known host on the planet since CPUs (other than 
perhaps some exotic DSP) do not have 24-bit words.  I have not checked 
to see what libtiff is really doing, but it seems to me that it is 
best for the libtiff API user if 24-bits are presented in big-endian 
network-byte-order and not swapped into an order which does not help 
any type of host.  If libtiff needs to swap data before it goes into 
the file in order to be complaint with Chris Cox's draft specification 
(and Photoshop CS2), then that is fine.

Opinions?

Bob
======================================
Bob Friesenhahn
bfriesen@simple.dallas.tx.us, http://www.simplesystems.org/users/bfriesen/
GraphicsMagick Maintainer,    http://www.GraphicsMagick.org/