2006.04.02 16:19 "Re: [Tiff] 16-bit TIFF to 8-bit BMP/TIF ???", by Bob Friesenhahn

Sorry for the late reply. What I am getting with most software packages is an entirely black image. Is there a way of veiwing the data form teh 16-bit unsigned TIFF without libtiff automatically converting to 8-bit i.e. view 16-bit data? I can manually convert all values using a square root (changing into the desired 8-bit 0-255 whilst keeping proportions).

   This may be a slow memory inefficient method but at
this stage I would like this functionality.

The libtiff APIs provide support for accessing the original values but I don't know that anything more than 8-bits is available from the libtiff utilities.

You might try GraphicsMagick (http://www.GraphicsMagick.org/) which is able to retrieve 16-bit TIFF data without any problem and provides a number of algorithms you could use to convert to 8-bit data.

Bob
======================================
Bob Friesenhahn
bfriesen@simple.dallas.tx.us, http://www.simplesystems.org/users/bfriesen/
GraphicsMagick Maintainer, http://www.GraphicsMagick.org/