AWARE SYSTEMS
TIFF and LibTiff Mail List Archive

Thread

2007.01.17 02:25 "[Tiff] Elevation Data", by Craig Bruce
2007.01.17 02:57 "Re: [Tiff] Elevation Data", by Bob Friesenhahn
2007.01.17 08:07 "Re: [Tiff] Elevation Data", by Joris Van Damme
2007.01.17 15:24 "RE: [Tiff] Elevation Data", by Ed Grissom
2007.01.17 15:55 "Re: [Tiff] Elevation Data", by Joris Van Damme
2007.01.17 16:03 "RE: [Tiff] Elevation Data", by Ed Grissom
2007.01.17 16:08 "Re: [Tiff] Elevation Data", by Bob Friesenhahn
2007.01.17 16:30 "Re: [Tiff] Elevation Data", by Joris Van Damme
2007.01.17 19:03 "Re: [Tiff] Elevation Data", by Frank Warmerdam
2007.01.17 17:28 "Re: [Tiff] Elevation Data", by Joris Van Damme
2007.01.17 21:18 "Re: [Tiff] Elevation Data", by Frank Warmerdam
2007.01.17 16:51 "Re: [Tiff] Elevation Data", by Gerben Vos
2007.01.17 18:03 "Re: [Tiff] Elevation Data", by Joris Van Damme
2007.01.17 16:27 "Re: [Tiff] Elevation Data", by Frank Warmerdam
2007.01.17 19:00 "Re: [Tiff] Elevation Data", by Joris Van Damme
2007.01.17 21:51 "Re: [Tiff] Elevation Data", by Frank Warmerdam
2007.01.17 19:26 "RE: [Tiff] Elevation Data", by Ed Grissom
2007.01.17 16:20 "Re: [Tiff] Elevation Data", by Joris Van Damme
2007.01.17 16:52 "RE: [Tiff] Elevation Data", by Ed Grissom
2007.01.17 17:20 "Re: [Tiff] Elevation Data", by Joris Van Damme
2007.01.17 20:00 "Re: [Tiff] Elevation Data", by Craig Bruce
2007.01.17 20:07 "Re: [Tiff] Elevation Data", by Joris Van Damme
2007.01.17 17:01 "Re: [Tiff] Elevation Data", by Bob Friesenhahn
2007.01.17 19:27 "Re: [Tiff] Elevation Data", by Frank Warmerdam
2007.01.17 18:35 "Re: [Tiff] Elevation Data", by Joris Van Damme
2007.01.17 21:08 "Re: [Tiff] Elevation Data", by Frank Warmerdam
2007.01.17 20:22 "Re: [Tiff] Elevation Data", by Joris Van Damme
2007.01.17 20:52 "Re: [Tiff] Elevation Data", by Joris Van Damme
2007.01.17 22:18 "Re: [Tiff] Elevation Data", by Bob Friesenhahn
2007.01.17 21:00 "Re: [Tiff] Elevation Data", by Bob Friesenhahn
2007.01.17 21:58 "Re: [Tiff] Elevation Data", by Joris Van Damme
2007.01.18 11:09 "Re: [Tiff] Elevation Data", by Andrey Kiselev
2007.01.17 03:35 "Re: [Tiff] Elevation Data", by Frank Warmerdam
2007.01.17 08:00 "Re: [Tiff] Elevation Data", by Joris Van Damme

2007.01.17 02:25 "[Tiff] Elevation Data", by Craig Bruce

I would like to write signed 16-bit elevation data to a TIFF image file, but according to the TIFF 6.0 specification, there doesn't appear to be a correct way to do this. The specification allows the use of the SampleFormat to specify that the samples are signed 16-bit integers, but this range of values is incompatible with the PhotometricInterpretation tag, which must be present. The obvious PhotometricInterpretation to use is BlackIsZero, but its range is defined as 0 to 2**nbits-1 (i.e., unsigned integers).

So, how does one make a correct image using a SampleFormat other than unsigned integer? What is the most compatible incorrect approach?

Also, is there a semantic difference between SMinSampleValue and MinSampleValue? The spec explicitly states that MinSampleValue is just statistical and isn't part of a valid-sample-range definition, but it's much more coy about SMinSampleValue. If it isn't part of a hard range definition, then how can one make an interoperable image with floating-point samples?

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Dr. Craig S. Bruce        | Ph 819-771-8303 x205 |             CubeWerx Inc.
Senior Software Developer |   Fax 819-771-8388   |  Gatineau, Québec, Canada
csbruce@cubewerx.com      |  http://csbruce.com/ |  http://www.cubewerx.com/
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             "Sixteen exabytes ought to be enough for anybody."