On the fly color HiPS generation

[tboch]

We had a prototype allowing one to generate dynamically color HiPS from existing HiPS datasets.
It would be great to revive it, taking advantage of the whole dynamic range of FITS tiles.

[bmatthieu3]

It is possible to do it by aladin lite (on client side) but in my opinion we should provide a better user api and extend it a little bit to make that feature more visible. It is quite hidden for the moment. Here is an example blending 3 hipses each mapped to a specific color. https://github.com/cds-astro/aladin-lite/blob/master/examples/al-additive-blend.html

Are you referring to that ?

[tboch]

Actually, I was referring to this: https://aladin.cds.unistra.fr/AladinLite/v3-preview/

Yes, you can do it in the current version, but it's hard to discover/understand. Having a dedicated UI for this would be great.

[bmatthieu3]

Ok thanks I understand more

[tboch]

This could be split down as:

• create the UI to let the user choose the HiPS components and the parameters
• add a new button to open this UI
• create a new API method createRGBComposite

Once the composite layer created, parameters (cuts, colors for each component, etc) could be updated through a dedicated UI.