LibTiff Mailing List

Roger,

> Let's see if I understand this...  The application interface simply calls
> the top-level functions, which are configured by TIFFClientOpen() to use the
> proper I/O interface routines for the type of computer and I/O (stream,
> file, buffer) called for.  Once thus configured, and with the platform
> independent autoconfiguration of the CODECs that occurs during opening of
> the TIFF itself, TIFFReadEncodedStrip() and TIFFWriteEncodedStrip() know
> where and how to process the data provided.  As a result, to do my TStream
> interface, I need only write TIFFStreamReadProc(), TIFFStreamWriteProc(),
> TIFFStreamSeekProc(), TIFFStreamCloseProc(), TIFFStreamSizeProc(),
> TIFFNoMapProc(), and TIFFNoUnmapProc() and a TIFFOpenStream() that calls
> TIFFClientOpen() and passes it these function addresses.

That's about it!

> One remaining question, to which I know the answer is yes, but I need to
> know where to look for information:  Where do I find specifications or
> requirements for writing these routines for which pointers are passed in
> TIFFClientOpen()?

To the best of my knowledge, the TIFFOpen man page is the only documentation on
this.

http://www.remotesensing.org/libtiff/man/TIFFOpen.3tiff.html

I know for a fact that the TStream IO procedures in LibTiffDelphi.pas work, and
you've identified them, so the easiest way is probably to translate these short
routines to C. If you do, posting your translation here is a) a good way to have
second opinions on it, and b) a nice gift to an archive user that has the same
requirement.

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


AWARE [SYSTEMS]		Imaging expertise for the Delphi developer
		TIFF and LibTiff Mailing List Archive
	LibTiff Mailing List TIFF and LibTiff Mailing List Archive March 2005 Previous Thread Next Thread Previous by Thread Next by Thread Previous by Date Next by Date Contact The TIFF Mailing List Homepage This list is run by Frank Warmerdam Archive maintained by AWare Systems	Thread 2005.03.15 17:56 "Need to write CCITT T.6 encoded TIFF file data directly to memory buffer", by Roger Watkins 2005.03.15 18:09 "Re: Need to write CCITT T.6 encoded TIFF file data directly tomemory buffer", by Joris Van Damme 2005.03.16 18:08 "Re: Need to write CCITT T.6 encoded TIFF file data directly tomemory buffer", by Roger Watkins 2005.03.16 19:38 "Re: Need to write CCITT T.6 encoded TIFF file data directlytomemory buffer", by Joris Van Damme 2005.03.16 22:04 "Re: Need to write CCITT T.6 encoded TIFF file data directlytomemory buffer", by Roger Watkins 2005.03.16 22:24 "Re: Need to write CCITT T.6 encoded TIFF file datadirectlytomemory buffer", by Joris Van Damme 2005.03.17 02:35 "Re: Need to write CCITT T.6 encoded TIFF file datadirectlytomemory buffer", by Roger Watkins 2005.03.17 03:10 "Re: Need to write CCITT T.6 encoded TIFF filedatadirectlytomemory buffer", by Joris Van Damme 2005.03.17 23:57 "Re: Need to write CCITT T.6 encoded TIFF file datadirectlytomemory buffer", by Roger Watkins 2005.03.16 22:24 "Re: Need to write CCITT T.6 encoded TIFF file datadirectlytomemory buffer", by Joris Van Damme Roger, > Let's see if I understand this... The application interface simply calls > the top-level functions, which are configured by TIFFClientOpen() to use the > proper I/O interface routines for the type of computer and I/O (stream, > file, buffer) called for. Once thus configured, and with the platform > independent autoconfiguration of the CODECs that occurs during opening of > the TIFF itself, TIFFReadEncodedStrip() and TIFFWriteEncodedStrip() know > where and how to process the data provided. As a result, to do my TStream > interface, I need only write TIFFStreamReadProc(), TIFFStreamWriteProc(), > TIFFStreamSeekProc(), TIFFStreamCloseProc(), TIFFStreamSizeProc(), > TIFFNoMapProc(), and TIFFNoUnmapProc() and a TIFFOpenStream() that calls > TIFFClientOpen() and passes it these function addresses. That's about it! > One remaining question, to which I know the answer is yes, but I need to > know where to look for information: Where do I find specifications or > requirements for writing these routines for which pointers are passed in > TIFFClientOpen()? To the best of my knowledge, the TIFFOpen man page is the only documentation on this. http://www.remotesensing.org/libtiff/man/TIFFOpen.3tiff.html I know for a fact that the TStream IO procedures in LibTiffDelphi.pas work, and you've identified them, so the easiest way is probably to translate these short routines to C. If you do, posting your translation here is a) a good way to have second opinions on it, and b) a nice gift to an archive user that has the same requirement. 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

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2005.03.16 22:24 "Re: Need to write CCITT T.6 encoded TIFF file datadirectlytomemory buffer", by Joris Van Damme