2008.05.17 19:22 "Re: [Tiff] 32 bit samples", by Bob Friesenhahn

Resend my question. Guess this list only likes plain text?

We saw your original message, but of course plain text is better.

Hopefully you did not expect to be peppered with 1000 response emails from all the people who do NOT have experience with http://seamless.usgs.gov/website/seamless/viewer.htm? :-)

An application using libtiff can use it to retrieve 32 bit float samples. The problem is that 32 bit samples can represent almost anything and there is no one way to create a pleasing 8bit/sample RGB image from it. It is up to the application to decide what to do with the data.

The GDAL package (http://www.gdal.org/) is likely capable of dealing with these files, but I have no experience with GDAL so I can't say.

My own software (GraphicsMagick, http://www.GraphicsMagick.org/) can read floating-point TIFF files but it may require some user direction in order to obtain reasonable results.

I did not know how to use the seamless.usgs.gov site. I did download a bundle of large files but did not find any TIFF files therein.

Bob

From: Garry Petrie [mailto:garry@petries.net] Sent: Friday, May 16, 2008 2:25 PM To: 'tiff@lists.maptools.org' Subject: 32 bit samples

I was wondering if anyone has experience with

http://seamless.usgs.gov/website/seamless/viewer.htm

gp

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