			       NSTiffExif

                  Read NikonScan TIFF Exif/MakerNote Tags

                   Brendt Wohlberg  software@wohlberg.net

               [Most recent modification: 5 April 2005]

Functionality:

   This program extracts the scanner setting information embedded in
   TIFF files written by the NikonScan driver software for Nikon film
   scanners. This information is stored in an IFD which is not 
   accessible using standard TIFF utilities. If nsexif is compiled
   with libbz2 support, it will attempt to uncompress the header of a
   bzip2 compressed TIFF file before reading the scanner information.

Usage:

   nsexif [-c] [-h] filename ...

   -c  Attempt to correct error in negative analog gains. When
       reloading files into NikonScan, the displayed analog gains, 
       when negative, are 0.01 greater than the value selected on
       scanning. No correction is possible at 0.00, which cannot 
       be distinguished from -0.01.
        
   -h  Display usage information.

 
Requirements:
  
  * libtiff (see http://www.libtiff.org/)
  * libbzip2 (http://sources.redhat.com/bzip2/) [Optional]

Note:

  This software has only been tested under linux/i386, but is expected
  to also work under other versions of UNIX running on other machine
  architectures. Operations appears to be correct for files generated
  by NikonScan 3.12 and 4.0. Error reports and enhancement suggestions
  are welcomed. Previous versions of this package were called
  "NSTifftags".

References:

  The TIFF tag access code was based on that used in the "tiffdump"
  utility distributed with libtiff. The "exifprobe" utility (see
  http://directory.fsf.org/webauth/iview/exifprobe.html) was
  invaluable in decoding the structure of the hidden tags used to
  store the scanner settings.

License:

  This software is made available under the terms of the GPL (see file
  included in this distribution).


