[S2MPC] Colour scale adjustment

When viewing RGB images, SNAP does its own colour scale adjustment (I suppose based on the histogram) independently on each band.
Most of the time it looks OK, but on highly contrasted images the result can be very strange. I have an example of an image of the Mediterranean sea with just a small bit of land with a very bright rooftop. When viewed with SNAP the sea looks green.
I found that for most images adjusting RGB bands to be within 0-500 digital counts is a very good default setting.

I would recommend to:

  1. use this setting as a default
  2. or at least to ensure that the RGB colour scales are consistent.

Sébastien CLERC
S2MPC

I filed an issue for it so that this idea is not lost :
https://senbox.atlassian.net/browse/SIITBX-178

I would like to suggest, in addition to the recommendation from Sébastien, to allow the SNAP users to load histogram min/max values from files.

My suggestions is to insert a new section in the RGB-Image Profile Files (.rgb) to allow the definition of min/max values for each of the RGB bands. This option should be also available in ‘pconvert’ command line tool for the generation of RGB converted images using user defined histogram min/max values.

Federico

I faced same result for agricultural area having big water basin. All I could obtain was greenish color of the water. I used 432 as RGB combination to visualize the L2A images in SNAP as suggested in the RGB image window dialog, I have two i mages of one and the same area from different years - one is processed from L1C with sen2cor the other is downloaded as L2A from ESA scihub.

The same result for both images is in QGIS.

Any suggestions/comments?