AWARE [SYSTEMS]
AWare Systems, , Home TIFF and LibTiff Mailing List Archive

LibTiff Mailing List

TIFF and LibTiff Mailing List Archive
November 2012

Previous Thread
Next Thread

Previous by Thread
Next by Thread

Previous by Date
Next by Date

Contact

The TIFF Mailing List Homepage
Archive maintained by AWare Systems



New Datamatrix section



Valid HTML 4.01!



Thread

2012.11.24 00:09 "help writing thumbnails to TIFF file?", by Paul Heckbert
2012.11.24 00:46 "Re: help writing thumbnails to TIFF file?", by Joris Van Damme
2012.11.25 13:01 "Re: help writing thumbnails to TIFF file?", by Edward Lam
2012.11.25 15:08 "Re: help writing thumbnails to TIFF file?", by Joris Van Damme
2012.11.27 02:10 "Re: help writing thumbnails to TIFF file?", by Paul Heckbert
2012.11.27 03:25 "Re: help writing thumbnails to TIFF file?", by Bob Friesenhahn
2012.11.27 13:12 "Re: help writing thumbnails to TIFF file?", by Joris Van Damme
2012.11.27 14:38 "Re: help writing thumbnails to TIFF file?", by Olivier Paquet
2012.11.28 03:06 "Re: help writing thumbnails to TIFF file?", by Olivier Paquet
2012.12.08 04:35 "Re: help writing thumbnails to TIFF file?", by Paul Heckbert
2012.11.27 18:09 "Re: help writing thumbnails to TIFF file?", by Daniel Mccoy

2012.11.28 03:06 "Re: help writing thumbnails to TIFF file?", by Olivier Paquet

On Tue, Nov 27, 2012 at 9:38 AM, Olivier Paquet
<olivier.paquet@gmail.com> wrote:
>> My current hypothesis: TIFFCheckpointDirectory works fine if you're
>> writing only one directory, but it's buggy when there are multiple
>> directories.
>
> Quite possible. It works by keeping the directory in memory for
> further checkpoints or the final write. Getting it to work with
> multiple directories requires rereading them (with TIFFSetDirectory)
> which is very different. It does look like it should work so it can't
> be that far from actually working. I will try to find some time to
> take a closer look.

After trying a few ugly hacks in libtiff, I got an apparently valid
file with both libtiff 3 and 4 by adding a TIFFWriteDirectory call
after each of your TIFFCheckpointDirectory calls. The file looks good
in tiffinfo and tiffdump, will split with tiffsplit and opens in KDE's
viewer (okular) as two pages of different resolution. tiffdump shows
the layout to be IFD0, IFD1, data for IFD1, data for IFD0. I don't
know how future-proof this is but it at least appears to work for now,
in this specific case. Oh and it even passes valgrind :)

Olivier