AWARE SYSTEMS
TIFF and LibTiff Mail List Archive

Thread

1994.04.19 20:54 "TIFF Tags for remote-sensing", by Randolf Gladish
1994.04.22 09:03 "Re: TIFF Tags for remote-sensing", by Karsten Spang
1994.04.22 13:10 "Re: TIFF Tags for remote-sensing", by Francois Gauthier

1994.04.22 09:03 "Re: TIFF Tags for remote-sensing", by Karsten Spang

I was wondering if there has been any work regarding the use of TIFF to store multispectral data sets. Most TIFF implementations place severe (for MS data) restrictions on the number of samples per pixel (bands) usually 3 or 4. This is completely inadequate for remote-sensing.

In principle there is no restriction on the number of samples in a TIFF image. All the samples must have the same resolution, though. (I seem to recall that the far infrared band of Landsat only has half the resolution of the rest)

The main problem is that there is no suitable value for the photometric interpretaion tag. I suggest that you contact Aldus and request that a new value "Multispectral" is included in the next version. Alternatively, you may want a private value. The tag has no default value, nor is it a "required" field, thus you may simply omit it. This is "right" in the sense, that multispectral data have no real colors per se, only when you assign colors to the bands, the picture comes out in (false) colors.

Karsten

P.S. (just speculating) New values of the resolution unit tag may be also beneficial to remote sensing applications, including pixels per meter and pixels per kilometer. You may also want new tags for describing the geographical area depicted, wavelenght intervals for each sample,...

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