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July 2004

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2004.07.01 23:09 "MINISBLACK not working for COMPRESSION_CCITT_T6 document", by Ron James

2004.07.02 15:28 "Re: MINISBLACK not working for COMPRESSION_CCITT_T6 document", by Jason Summers

2004.07.02 15:28 "Re: MINISBLACK not working for COMPRESSION_CCITT_T6 document", by Jason Summers

James, Ron wrote:
> I'm making the following calls:
> 
>     TIFFSetField(iTFile, TIFFTAG_COMPRESSION, COMPRESSION_CCITT_T6);
> 
>     TIFFSetField(iTFile, TIFFTAG_PHOTOMETRIC, PHOTOMETRIC_MINISBLACK);
> 
> And my document is created in reverse  - i.e. white text on a black
> background.
> ...
>
> How can I get a black text on white document using CCITT_T6?

The TIFF viewer you're testing this with was apparently written by 
someone who never bothered to read the TIFF specification. 
Unfortunately, there are a lot of such viewers out there.

If you need to support buggy viewers, never use MINISBLACK with CCITT 
compression. Only use MINISWHITE. You will probably have to invert the 
image data yourself before passing it to libtiff.