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June 2010
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2010.06.12 12:49 "Re: libtiff 3.9.3 released --> Regression in writing JPEG compressed TIFF", by Even Rouault
Typo fix: The correct GDAL commandline to produce JPEG compressed TIFF is : gdal_translate -co COMPRESS=JPEG in.tif out.tif Le Saturday 12 June 2010 14:03:01 Even Rouault, vous avez écrit : > Folks, > > I've just tested libtiff 3.9.3 with GDAL autotest suite (and GDAL SVN > head), and I'm seeing failures that I do not get with libtiff 3.9.2. > > Those new failures are in tiff_write_13(), tiff_write_54() and > tiff_write_58() > (http://trac.osgeo.org/gdal/browser/trunk/autotest/gcore/tiff_write.py) All > 3 are related to reading JPEG compressed TIFF that have just been created. > Basically when I open the image generate by tiff_write_13() I see a black > square for the first tile of the image (or a whole black image for stripped > images). This can be easily reproduced with running: gdal_translate -of > JPEG in.tif out.tif and opening out.tif afterwards > > There were a few changes in tif_jpeg.c between 3.9.2 and 3.9.3. I've found > that reverting the following change in TIFFInitJPEG() fixes the 3 above > failures. > > 2010-02-22 Lee Howard <XXX@XXX> > > * libtiff/tif_jpeg.c: Do not generate a JPEGTables tag when creating > the JPEG TIFF as is is not required in order to prevent it from > being unused and filled with invalid data. (Leave it to be > generated by later activity.) > http://bugzilla.maptools.org/show_bug.cgi?id=2135 > > The change was to comment the TIFFSetFieldBit(tif, FIELD_JPEGTABLES) call. > > /* > The following line assumes incorrectly that all JPEG-in-TIFF files will > have a JPEGTABLES tag generated and causes null-filled JPEGTABLES tags to > be written > when the JPEG data is placed with TIFFWriteRawStrip. The field bit should > be set, anyway, later when actual JPEGTABLES header is generated, so > removing it here hopefully is harmless. > TIFFSetFieldBit(tif, FIELD_JPEGTABLES); > */ > > Frank got problems with that change (see comment #2 in > http://bugzilla.maptools.org/show_bug.cgi?id=2135) and found a solution > that implied changing TIFFFlush() that has gone in libtiff 4.0.0beta6 (GDAL > autotest suite is happy with 4.0.0beta6), but not in 3.9 branch. > > Change in 4.0 branch : > > 2010-03-31 Frank Warmerdam <XXX@XXX> > > * libtiff/tif_flush.c: Use TIFFRewriteDirectory() when flushing > directories so previously placed directories will be migrated to > the end of file if needed. > > So I've tested the following change, similar to the one done in trunk : > > --- libtiff/tif_flush.c.bak 2010-06-12 13:25:45.000000000 +0200 > +++ libtiff/tif_flush.c 2010-06-12 13:25:52.000000000 +0200 > @@ -37,7 +37,7 @@ > if (!TIFFFlushData(tif)) > return (0); > if ((tif->tif_flags & TIFF_DIRTYDIRECT) && > - !TIFFWriteDirectory(tif)) > + !TIFFRewriteDirectory(tif)) > return (0); > } > return (1); > > and this fixes the tiff_write_13(), tiff_write_54() and tiff_write_58() > failures, but it causes a new failure in tiff_write_72(), which is not > critical but a sign that the directory is rewritten a bit too aggressively > (leading to larger files than necessary). > > But TIFFFlush() in libtiff 4.0 has changed quite significantly in > comparison to libtiff 3.X, and it looks like efforts were made to avoid > (re)writing the directory when only strip/tile map has been altered. > > So at that point, I'm not sure which solution is appropriate for 3.9 branch > : (1) reverting the change in TIFFInitJPEG() --> means "unfixing" > http://bugzilla.maptools.org/show_bug.cgi?id=2135 > (2) replace TIFFWriteDirectory() by TIFFRewriteDirectory() in TIFFFlush() > --> produce files a bit larger than before, due to unnecessary directory > rewriting > (3) = (2) + porting the other changes done in 4.0 branch in TIFFFlush() > > Note that I do not observe any problem when creating JPEG compressed TIFF > with tiffcp. By looking at the produced file, it looks like tiffcp only > writes the directory at the end of the process, whereas GDAL GTiff driver > does an early "crystalization" (GTiffDataset::Crystalize() method) to "make > sure that the directory information is written out for a new file, require > before writing any imagery data." > > Best regards, > > Even > > Le Saturday 12 June 2010 01:44:07 Bob Friesenhahn, vous avez écrit : > > Libtiff 3.9.3 is now released. This releases fixes various bugs which > > which were reported via libtiff Bugzilla as well as some security > > issues. > > > > Please visit http://www.remotesensing.org/libtiff/v3.9.3.html to read > > about the release, or to download the software. > > > > Thanks, > > > > Bob > > _______________________________________________ > Tiff mailing list: Tiff@lists.maptools.org > http://lists.maptools.org/mailman/listinfo/tiff > http://www.remotesensing.org/libtiff/