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TIFF and LibTiff Mail List Archive

Thread

2004.07.01 23:09 "[Tiff] MINISBLACK not working for COMPRESSION_CCITT_T6 document", by James, Ron
2004.07.02 15:28 "Re: [Tiff] MINISBLACK not working for COMPRESSION_CCITT_T6 document", by Jason Summers

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

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.