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
September 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

2007.09.20 21:03 "libtiff4, and the size of STRIPOFFSETs and TILEOFFSETs", by Frank Warmerdam
2007.09.20 22:20 "Re: libtiff4, and the size of STRIPOFFSETs and TILEOFFSETs", by Andrey Kiselev
2007.09.21 17:46 "Re: libtiff4, and the size of STRIPOFFSETs and TILEOFFSETs", by Joris Van Damme
2007.10.04 15:05 "Re: libtiff4, and the size of STRIPOFFSETs and TILEOFFSETs", by Frank Warmerdam
2007.10.05 05:45 "Re: libtiff4, and the size of STRIPOFFSETs and TILEOFFSETs", by Joris Van Damme

2007.10.05 05:45 "Re: libtiff4, and the size of STRIPOFFSETs and TILEOFFSETs", by Joris Van Damme

Frank,

Frank Warmerdam wrote:
> I have decided that my current approach of rewriting the whole
> directory is too risk-prone (ie. still doesn't work with legitimate 
> pre-existing
> files) so I'm going to change my code to include custom mechanisms to
> update the strip/tile offset/size tags "in place" without using the
> libtiff "write directory" mechanism.  Once done, I'll back out the
> changes I mentioned above.
>
> I'm considering implementing this as a sort of auxilary libtiff
> function. Something like "TIFFRewriteImageOffsetSize()" that would
> update the current directory on disk with the "in memory" strip/tile 
> offsets and
> sizes. This might result in moving the lists to the end of the file
> if they change in size (ie. shorts become longs, etc).  Do others
> feel this would be a useful function to have available in libtiff?

This sounds like it could be a first experiment towards a more general 
control over actual tag values and value manipulation, which I feel is 
something a lot of LibTiff users would like to see. Even more importantly, 
it sounds like we'll no longer need the current hack and we'll be able to 
restore the original function that writes Long or Long8 depending on value, 
so as to be able to reuse this in such a more general control interface, 
which was the intention all along. So I'm all for.


Best regards,

Joris Van Damme
info@awaresystems.be
http://www.awaresystems.be/
Download your free TIFF tag viewer for windows here:
http://www.awaresystems.be/imaging/tiff/astifftagviewer.html