AWARE SYSTEMS
TIFF and LibTiff Mail List Archive

Thread

2009.02.12 21:10 "[Tiff] warning and errors", by Philip Watkinson
2009.02.12 22:53 "Re: [Tiff] warning and errors", by Frank Warmerdam
2009.02.12 23:06 "Re: [Tiff] warning and errors", by Philip Watkinson
2009.02.19 17:17 "[Tiff] Bug in tiff_jpeg.c dealing with pre-subsampled ycbcr data passed to TIFFWriteEncodedXxx", by
[...]

2009.02.12 22:53 "Re: [Tiff] warning and errors", by Frank Warmerdam

I'm using Libtiff and getting the warning "unknown field with tag 34665 (0x8769) encountered". Joris stated the following about the tag in some correspondence:

The warning doesn't really matter, unless you're specifically interested in the EXIF information of course. Image decoding using LibTiff should still work fine, the warning can be safely ignored.

Can I assume that all warning still produce a good image?

Philip,

No, this is not a safe assumption, but it is true that the "unknown field" warning is harmless. It normally just indicates the presents of a (possibly private) tag not in the core standard.

There are some warnings that may indicate the image is likely to be wrong. But generally speaking the library will attempt to continue processing and you are *likely* to get something useful when you see warnings.

Best regards,
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