Pulling night-shine from images of moons, how can i attempt night-shine extraction in Gimp on a RAW image? Options

[TrappistPlanets]

I tried to pull any possible nightshine from this umbriel RAW image (below), but i keep getting nothing, other than some terminator stuff, same goes for Triton, and Oberon (ik the night-shine for the 2 uranian moons would be low resolution, bs it was not the closes approach point like it was for Titania).


Also, is it possible to extract any higher detail plutoshine from RAW half phase Charon images (pluto is pretty bright!)?

i also want to try to pull out more detail of this stuff way beyond into the darkside of this image i found on one of the post encounter threads



so this is where i need help, how can i extract night-shine (either from atmosphere or from a nearby large object (like a planet)) in gimp?

[Phil Stooke]

Regarding the Uranian satellites illuminated by light reflected off the planet: you can only see it if you are looking at the part of the satellite which faces Uranus - if you are seeing the region facing away from the planet you won't see anything. In the absolutely ideal case you would see 50% of the moon lit by the sun and another 25% lit by the planet, but viewing directions will not always cooperate. You might like to see this blog post by Ted Stryk:

https://www.planetary.org/articles/1362


And this is the LPSC abstract that started it all:

https://www.lpi.usra.edu/meetings/lpsc2001/pdf/1074.pdf

Believe it or not, nobody had noticed this before. I can't believe it was over 20 years ago.

Phil

[TrappistPlanets]

Regarding the Uranian satellites illuminated by light reflected off the planet: you can only see it if you are looking at the part of the satellite which faces Uranus - if you are seeing the region facing away from the planet you won't see anything. In the absolutely ideal case you would see 50% of the moon lit by the sun and another 25% lit by the planet, but viewing directions will not always cooperate. You might like to see this blog post by Ted Stryk:

https://www.planetary.org/articles/1362


And this is the LPSC abstract that started it all:

https://www.lpi.usra.edu/meetings/lpsc2001/pdf/1074.pdf

Believe it or not, nobody had noticed this before. I can't believe it was over 20 years ago.

Phil

i down-sampled and messed with brightness and contrast, but i still can't see much detail other than some craters (marked in red in the pic with marks on it), and some faults (marked in yellow in the pic with marks on it)



how did how did ted remove all the instrument noise, that Pluto image is so noisy and makes it hard to see much detail in the night side stuff, other than some craters and faults/cracks

[JRehling]

how did how did ted remove all the instrument noise

The paper that Phil linked to discusses that. High pass filters accomplish what I suggested with downsampling.

If the relatively brief description doesn't make this clear, it was obviously a lot of hard work, not just trying one or two things.

The removal of instrument noise can often be served to some extent by removing the noise seen in dark frames, or, if you lack those, the dark areas of other frames. It is essential to find ones with the same capture parameters.

I think you're greatly underestimating the amount of difficult, persistent, autonomous effort that is required. This isn't going to be something where you skim the manual, try one thing, quote a link without reading what was in the link, and expect to be done. If you're asking other people how to do image processing, and expect to get a result that they haven't already gotten, you won't get anywhere. We all have image processing software. The careful, painstaking, laborious, autonomous effort is the thing in short supply, not access to image processing software.

On another note, circular dark spots in those areas need not be craters. Instrument artifacts are often circular, Pluto is known to have circular landforms that do not resemble impact craters, and as I noted earlier, the atmosphere itself introduces multiple sources of noise.

[TrappistPlanets]

The paper that Phil linked to discusses that. High pass filters accomplish what I suggested with downsampling.

If the relatively brief description doesn't make this clear, it was obviously a lot of hard work, not just trying one or two things.

The removal of instrument noise can often be served to some extent by removing the noise seen in dark frames, or, if you lack those, the dark areas of other frames. It is essential to find ones with the same capture parameters.

I think you're greatly underestimating the amount of difficult, persistent, autonomous effort that is required. This isn't going to be something where you skim the manual, try one thing, quote a link without reading what was in the link, and expect to be done. If you're asking other people how to do image processing, and expect to get a result that they haven't already gotten, you won't get anywhere. We all have image processing software. The careful, painstaking, laborious, autonomous effort is the thing in short supply, not access to image processing software.

On another note, circular dark spots in those areas need not be craters. Instrument artifacts are often circular, Pluto is known to have circular landforms that do not resemble impact craters, and as I noted earlier, the atmosphere itself introduces multiple sources of noise.

what about the possible cracks i marked in yellow, is that noise or am i onto something there