2006.04.14 17:02 "Re: [Tiff] LibTiffDelphi problem with WriteEncodedStrip Newbee", by Joris Van Damme

Thorsten,

Please keep all mail that can be of public interest inside the mailing list. This can be a good thread, useful to many.

Sorry for that, it's the first mailing list I joined. Hopefully I did it right this time ;-)

Yes, you did perfectly fine. Thank you.

A complete adoption to save a pf1bit Bitmap to a G4 compressed TIFF, may look somewhat like this:

Thank you for your code, but it didn't work, and I can't figure out, what wents wrong. I tried to understand your code, but there are still some questions... Maybe you can help me

  RowSize:=((Bitmap.Width+7) div 8);

Why did you add 7 here? To get a multiple of 8?

I believe Bernie answered that perfectly. Another approach is, substitute Bitmap.Width with some values like 1,7, 8, and 9, and manually calculate RowSize. You'll find that the formulae fits, RowSize is exactly the number of bytes that is required to store Bitmap.Width subsequent bits.

Stepping through code, trying to "manually execute", is often a recommendable way to gain more insight.

The Result of the procedure is a file without data. The only thing included is the tiff-header. Maybe you can check your code? I'm not able to figure out, what's wrong.

I've double-checked my draft attempt, and it works perfectly fine over here. Except that you should replace PHOTOMETRIC_MINISWHITE with PHOTOMETRIC_MINISBLACK, as I suspected already.

Try again. If it still doesn't work, mail me your zipped bitmap and relevant code, and I'll take a look.

Best regards,

Joris Van Damme
info@awaresystems.be
http://www.awaresystems.be/
Download your free TIFF tag viewer for windows here:
http://www.awaresystems.be/imaging/tiff/astifftagviewer.html