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IR colour enhancement

Matt Painter edited this page Oct 30, 2020 · 22 revisions

A colour lookup table (CLUT) can be used with Sanchez to use a false palette for part or all of the IR image based on intensity.

This IR enhancement feature can be applied to all modes via the -c / --clut <intensity> argument.

<img src="images/clut/thumbs/full.jpg" width="39%><img src="images/clut/thumbs/partial.jpg" width="39%>

Intensity ranges

IR images sent from geostationary satellites map pixel intensity to temperature. To simplify development, Sanchez uses a 0.0 - 1.0 intensity scale; 0 being the coldest temperature in the image, and 1.0 being the hottest.

Sample usage

Full image replaced with CLUT using default red/blue gradient:

sanchez -o output\geostationary -s sample-images -c 0-1

Full image replaced with CLUT using custom gradient:

sanchez -o output\geostationary -s sample-images -c 0-1 -g Resources\Gradients\Purple-Yellow.json

Partial temperature range replaced with CLUT

sanchez -o output\geostationary -s sample-images -c 0.7-1

Caveat

Due to the inaccuracies inherent in not mapping pixel intensity to temperature, this feature should not be used for scientific purposes. If you are wishing to accurately apply a clut to images created by GK-2A, see GEO-KOMPSAT-2A IR Colour Enhancement.