TIFFTAG_RICHTIFFIPTC vs my life...

[Chris Losinger]

        There are a number of TIFF writers out there which write IPTC data
with the type TIFF_UNDEFINED instead of TIFF_LONG. And this means
that LibTiff ignores those tags - much to my users' dismay.

        So, has anyone found a way to teach LibTiff to allow
TIFFTAG_RICHTIFFIPTC to be read when it's been saved as TIFF_UNDEFINED ?

        I can kindof see a way to do it - starting by teaching the 'wrong
data type' check in TIFFReadDirectory to allow the exception; but
then OkToChangeTag tells TIFFVSetField to use the built-in type for
that tag (TIFF_LONG instead of TIFF_UNDEFINIED), and that means all
the mallocs and memcpys which follow are too large by a factor of 4.

        Without teaching OkToChangeTag about the exception, and then finding
the next snag, which could take forever, I was hoping to see that
someone else had found a solid solution to the problem and would be
willing to share...

        Anyone ?

        -c
----
Chris Losinger
losinger@...
smallest@...          http://www.smalleranimals.com

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[Chris Losinger]

         and by OkToChangeTag, i meant _TIFFFindFieldInfo.
         sorry. :)

         problem remains the same, however.
         -c

At 12:38 PM 9/24/2009, Chris Losinger wrote:

>..
>         I can kindof see a way to do it - starting by teaching the 'wrong
>data type' check in TIFFReadDirectory to allow the exception; but
>then OkToChangeTag tells TIFFVSetField to use the built-in type for
>that tag (TIFF_LONG instead of TIFF_UNDEFINIED), and that means all
>the mallocs and memcpys which follow are too large by a factor of 4.
>
>         Without teaching OkToChangeTag about the exception, and then finding
>the next snag, which could take forever, I was hoping to see that
>someone else had found a solid solution to the problem and would be
>willing to share...

----
Chris Losinger
losinger@...
smallest@...          http://www.smalleranimals.com

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[Tom Welsh]

I feel your pain. When I load a TIFF that was written by Photoshop,  I get the warning, "wrong data type 7 for "RichTIFFIPTC"; tag ignored". Have you found any way to deal with this?

Tom

Chris Losinger wrote:

         and by OkToChangeTag, i meant _TIFFFindFieldInfo.
         sorry. :)

         problem remains the same, however.
         -c

At 12:38 PM 9/24/2009, Chris Losinger wrote:

>..
>         I can kindof see a way to do it - starting by teaching the 'wrong
>data type' check in TIFFReadDirectory to allow the exception; but
>then OkToChangeTag tells TIFFVSetField to use the built-in type for
>that tag (TIFF_LONG instead of TIFF_UNDEFINIED), and that means all
>the mallocs and memcpys which follow are too large by a factor of 4.
>
>         Without teaching OkToChangeTag about the exception, and then finding
>the next snag, which could take forever, I was hoping to see that
>someone else had found a solid solution to the problem and would be
>willing to share...

----
Chris Losinger
[e-mail]
[e-mail]          http://www.smalleranimals.com

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