"There's more than one way to skin a cat"

The first image is part of an Arizona State University panorama composed from images captured on #Mars2020 Sol 4, "approximately simulating the colors of the scene that we would see if we were there viewing it ourselves."
https://mastcamz.asu.edu/galleries/mastcam-zs-first-high-resolution-mosaic-sol-4/?back=%2Fmars-images%2Fpanoramas-mosaics%2F%3Fitem_type%3D360-panoramas

The second image is the same but filtered for people with insensitivity to green.

When it comes to color perception or other sensory experience, things don't necessarily follow our preconceptions 😀

#GIMP

@65dBnoise

Colour perception varies more than most people realise.

I guess the folk that set up some of the M20 cameras and their image pipelines appreciate the raw images on the mission server more than others.

#cantpleaseeveryone

@stim3on @PaulHammond51
My concern here is visual perception of Martian terrain and how a viewer can make the most out of it. So I take a "high altitude" view on the subject, caring most for the end result.

Anyone who has ever dived deeper than 10m (or has seen pictures/movies) knows that everything at that depth looks blue-green, despite fish and corals still being colorful. If one needs to understand what goes on at the bottom of the sea, presenting one ...

1/4

scientists (and everyone else) use are made to improve perception of the object/process being observed. The objective is always to augment human perception with details hard to discern otherwise.

I believe that NASA follows the above as close as possible. When the task is to preserve color fidelity, they do that using calibration targets for each instrument, and other procedures pertinent to the task.

It's inconceivable to me that they don't make use of those facilities.

4/4

@65dBnoise And yeah, most such attempts are basically just "winging" it and are not based on physical properties.

While the NASA images are technically based on physical properties of the cameras, they completely ignore the correct mapping of those values to a display. In that way they are not much more useful in creating an authentic view than the approximated hobbyist attempts.

@65dBnoise Even though the rovers have color calibration targets, I have not seen a single paper that uses these to calculate a correction for accurate colors. In principle they could be used for this, but they are far from optimal because there are too few targets with too little variation.

That said, they are actually used for calibration processes, but none that concern color accuracy. They are only used to calibrate radiometric data, i.e. how much light energy is entering the camera.

@stim3on
Hm, I'm afraid I wouldn't know, since I'm by no means an expert.

I would expect the PDS to have calibrated images using well established procedures tailored to the purpose they are using them for, which is the most important criterion for them to spend time to meet. There are other areas where similar criteria apply, and it might make it appear as if they didn't care.

Not sure if the purpose of the (~live) pipeline, where we get the raw images from, is to provide calibrated images.