[gdal-dev] Extending GDAL Color Interpretation enumeration for infra-red bands (+ band wavelength) ?

[Scott]

Given so many possible uses of band data, promote the use of meta data 
embedded in the image to suggest how the image should be rendered.

There is no way to make everyone happy. To me, a raster is 
multidimensional data storage and has absolutely nothing to do with the 
data source. Trying to anticipate every possible use now and in the 
future would be quite the feat.

Scott

On 8/31/24 07:21, Even Rouault via gdal-dev wrote:
> Hi,
> 
> The GDAL Color Interpretation enumeration is a good start, but is quite 
> limited regarding band spectral properties with just Red, Green, Bland, 
> and nothing for other band wavelengths, particularly for infra-red.
> 
> I was looking a bit at the classifications at 
> https://en.wikipedia.org/wiki/Infrared#Regions , and there are several 
> ones, like the "commonly used subdivision scheme" (NIR, SWIR, MWIR, 
> LWIR, FIR) or "CIE division scheme" (IR-A, IR-B, IR-C) or "ISO 20743 
> scheme" (NIR, MIR, FIR).
> 
> My inclination would rather to re-use the STAC EO classification at 
> https://github.com/stac-extensions/eo?tab=readme-ov-file#common-band-names, which shows a lot of similarities with https://github.com/awesome-spectral-indices/awesome-spectral-indices#expressions , and has a nice mapping with a few popular instruments.
> 
> While we are it, should we standardize central wavelength and full width 
> half max (FWHM), has special properties of a bands rather than generic 
> text-based metadata, like:
> 
> double GDALRasterBand::GetCentralWaveLengthMicrometer() -> NaN if unknown
> double GDALRasterBand::GetFWHMMicrometer() -> NaN if unknown
> void GDALRasterBand::SetCentralWaveLengthMicrometer(double)
> void GDALRasterBand::SetFWHMMicrometer(double)
> 
> Or maybe just standardize a "CENTRAL_WAVELENGTH" and "FWHM" metadata 
> items in the "IMAGERY" metadata domain: 
> https://gdal.org/en/latest/user/raster_data_model.html#imagery-domain-remote-sensing ?
> 
> Thoughts?
> 
> Even
>