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TIFF and LibTiff Mail List Archive

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2017.04.28 20:38 "[Tiff] Interesting change/problem in LibTiff 4.0.7 with unsupported compressions", by
2017.05.02 12:56 "Re: [Tiff] Interesting change/problem in LibTiff 4.0.7 with unsupported compressions", by
2017.05.02 14:33 "Re: [Tiff] Interesting change/problem in LibTiff 4.0.7 with unsupported compressions", by Charles Auer

2017.05.02 12:56 "Re: [Tiff] Interesting change/problem in LibTiff 4.0.7 with unsupported compressions", by

Just wondering if anyone has thoughts on this problem. Once I posted it doesn't' seem to have made it into the archive which means maybe it didn't get through at all??

This is a interesting situation since most people don't expect an error just from enumerating the directory and reading the tags. Maybe a warning would be more appropriate specifically for an inability to detail out the compression specific tags maybe??

Thanks.

Mike

From: tiff-bounces@lists.maptools.org [mailto:tiff-bounces@lists.maptools.org] On Behalf Of Michael | Shiels [ MaS \ Software \ Inc ]

Sent: Friday, April 28, 2017 4:38 PM
To: tiff@lists.maptools.org

Subject: [Tiff] Interesting change/problem in LibTiff 4.0.7 with unsupported compressions

I found a decent change in the behavior of Libtiff - after I updated from

the 3.5.6/3.5.7 era to the most recent (yes 15 year jump!!)

Specifically this piece of code - basically ends up tripping an error if the
compression is not compiled/activated in the code. So you can't even
peruse/move through a file without tripping an error.

/*

* An opportunity for compression mode dependent tag fixup

*/

(*tif->tif_fixuptags)(tif);

Our engine specifically watches for errors and assumes it's pretty fatal -
when really it's kinda benign - UNLESS I want to extract the image data
itself, right??

Surely that should be pretty benign to just enumerate through a TIFF - even
if you don't support the compression of each page??

Mike