Perijove 1 (PJ1), August 27, 2016 Options

[PFK]

Thank you. I noticed that too.

As chemist, when I see all these I can't help thinking "Belousov Zhabotinsky"

[Brian Burns]

As chemist, when I see all these I can't help thinking "Belousov Zhabotinsky"

My first thought was nice triskelion near the pole -



from Newgrange.

It'll be great to have a complete composite view after future orbits.

[Gerald]

An attempt to enhance a larger crop of my level 1 version of image #06182 with some mix of consumer image processing software:

That's been a proof of concept test of which techniques to implement and apply.

[elakdawalla]

I just noticed that the JunoCam team added observation descriptions to their raw image page for PJ1 images. I added the information to my image index.

[Gerald]

Not sure, whether anyone noticed it - besides the planning team - image #C06168 seems to show a large orangish vortex, in the lower half of these draft attempts to enhance it:

[Roman Tkachenko]

Another attempt to reveal some features in image #06171

[Matt Brealey]

Brian Burns - Thanks so much for the suggestion of SpiceyPy! I’ve taken a quick look and it certainly seems slightly more accessible than the command line/C toolset. And your example is very helpful - I’ll start breaking that down tonight. I’ll take a look into ISIS too, as getting any help with the reprojection would be fantastic!

Roman : The images you’ve posted are excellent - I entirely agree with the ‘Starry Night’ reference, too

Gerald : The image you posted on the 10th is incredibly beautiful. I’d love to know how you’re achieving the levels of contrast present.

For those interested, I’ve finally finished my article explaining the Visual Effects techniques I used to create the images I posted back on page 3 of this thread, and you can find it here : Constructing Jupiter. The aim with the article was to serve as a suitable introduction to those with knowledge of JUNO but not of VFX, and hopefully vice versa too. If anyone has any questions however, just let me know.

Thanks again!

[mcaplinger]

For those interested, I’ve finally finished my article explaining the Visual Effects techniques I used...

Wow, thanks for writing this, it's very impressive. I'm amazed that you can do all this with essentially no knowledge of the imaging geometry, and while it's fairly manual, it doesn't look nearly as labor-intensive as I was expecting -- a combination of the specific tool and your familiarity with it. (While in theory I guess you could do all of this in Photoshop, I shudder to imagine how long it might take, not that I am a Photoshop expert.)

One minor note: thanks for referring to the black dots on the images as calibration marks -- but they're really undesirable imperfections in the filters that we didn't really want. If they were useful regardless, that was a nice benefit!

[Gerald]

Gerald : The image you posted on the 10th is incredibly beautiful. I’d love to know how you’re achieving the levels of contrast present.

Thanks! The beauty is 95% JunoCam and Jupiter, and 5% my processing.
The processing method isn't yet fully optimized nor formalized. Roughly speaking, apply the following steps:
Estimate the contribution of the light filtering by the haze, subtract most of it, stretch brightness of the resulting rather dark image, and try to divide away artifacts.
I've estimated haze and artifacts by averaging along one axis over a sufficiently large range (the result varies along the other axis), and assumed about 3/4 of the mean color contributed by haze.
I'm expecting, that further refinement and formalization will allow for better quality, and applicability to a wider range of images.

[Matt Brealey]

mcaplinger : Thank you, I’m really very glad you liked the article! I too was incredibly surprised at just how relevant the toolset ended up being for this type of work. In VFX, image quality is really the number one priority, so the tools used to manipulate raw film plates are really designed with that in mind. Using those same tools for the Juno imagery was entirely analogous to the process I’ve completed many times in the past, although if I’m honest I have to say I found these results much more interesting! You are entirely correct as well that this could all be done in Photoshop, although the scripting/expression-driven nature of Nuke really helps automate some of the slightly more laborious parts of the process.

And thanks for the clarification on the ‘calibration marks’! They were in-fact really quite useful in terms of showing off a very common part of the process, however I’ve now updated the article just to keep it as factual as possible.

One question I do have - in VFX we often shoot a checkerboard/grid pattern in order to test/view the distortion that is present in a given lens. I was wondering if any such images were taken for Junocam/if that’s a common part of your process, too?

Gerald : First of all, I would certainly be tempted to bump your processing percentage slightly higher! Thanks for breaking down your process, it’s a very fascinating read. It’s so very interesting to me that your knowledge of the subject matter allows you to understand the images in ways that I haven’t even really considered, and yet the core processing techniques that result are relatively familiar to me. I have a lot to learn, I think, so thank you again for putting up with the odd question here and there!

[Gerald]

Regarding

One question I do have - in VFX we often shoot a checkerboard/grid pattern in order to test/view the distortion that is present in a given lens. I was wondering if any such images were taken for Junocam/if that’s a common part of your process, too?

You may be interested in the JunoCam Calibration Report.
Although I don't know, whether the referenced files are publicly accessible.
Preliminary geometric calibration data are provided in the JunoCam paper, subsection 4.7. Although the residuals beyond Brownian K1 haven't yet been expressed in algebraic form. For the outer part of the JunoCam images I'm inclined to add at least a small Brownian K2, but that's still not quite perfect. I'm also not quite sure, whether the Brownian way to describe lense distortions is the best one, since it's essentially a Taylor polynomial, which tend to oscillate heavily when of higher order.
You may also like to take a look into the pdf, I've provided in May this year, as an introduction of which challenges to expect for JunoCam image processing.

I've done some calibration experiments with stars in cruise images. You'll find some of those attempts in the Juno PDS thread. The BSC star catalog can serve as a reference image in this case. It's necessary, however, to understand time delay integration (TDI) for the long-exposure images. My humble attempts to describe and understand straylight and interline smear can be found in a respective dedicated thread. This is far from completed, but currently processing of the Jupiter images is of higher priority.
Thanks for scoring my processing of the above image higher. But if you take a look into the provided pdf articles in these threads, you'll know, why I'm scoring my PJ1 image enhancement experiments low in comparison, at least regarding the level of my portion of accomplished technical challenges.
-- I'd think, continuing detailed technical discussions about camera calibration with means other than PJ1 images would be better-suited in the respective threads.

[Brian Burns]

For those interested, I’ve finally finished my article explaining the Visual Effects techniques I used to create the images I posted back on page 3 of this thread, and you can find it here : Constructing Jupiter. The aim with the article was to serve as a suitable introduction to those with knowledge of JUNO but not of VFX, and hopefully vice versa too. If anyone has any questions however, just let me know.

Thanks for the great writeup! I hadn't understood the intricacies of assembling the JunoCam images, and it's interesting to learn about another image processing system. And apparently it's free for non-commercial use (normally $9300 - quite a bargain!) - https://www.thefoundry.co.uk/products/nuke/buy/ down at the bottom.

I like how you can warp and align channels so easily - that would be pretty useful for Voyager images where there was a lot of movement between the channels. But I wonder why there was a need for so much adjustment for JunoCam, if the different channels were taken at the same time?

This is probably my favorite image from Juno so far - nice colors -



I'm not sure ISIS will be usable with the Juno images yet - there's an issue filed here https://isis.astrogeology.usgs.gov/fixit/issues/1461 for making a Juno camera model. And I'm not sure how many people here use ISIS, aside from JohnVV - he started a thread here - http://www.unmannedspaceflight.com/index.php?showtopic=8198. But maybe you could achieve the same thing with your system + SPICE data, and projecting an image onto a sphere.

[Gerald]

ISIS3 has foreseen pushframe cameras. So, it should be feasible to write a JunoCam subclass. But I'm not sure, whether there is a budget, since science-grade calibration hasn't been in the package. In SPICE there is provided a JunoCam stub, at least.
To stay independent, I've written another system (also in C++, like ISIS3), with additional calibration capabilities, but specific for JunoCam, and not designed under shipping, usability or extensibility considerations.

[mcaplinger]

One question I do have - in VFX we often shoot a checkerboard/grid pattern in order to test/view the distortion that is present in a given lens. I was wondering if any such images were taken for Junocam/if that’s a common part of your process, too?

For a fast, wide-angle, fixed-focus lens you need an impractically large grid target to fill the field. For more recent cameras we use the OpenCV calibration software, which uses multiple images of smaller dot targets at different locations in the field. For Junocam we used a mixture of optical prescription data and dot targets, but it hasn't been completely satisfactory, and the cruise star imaging hasn't provided us with the data I'd hoped it would for reasons we still don't completely understand.

[mcaplinger]

I'm not sure ISIS will be usable with the Juno images yet...

We've contacted USGS about this but I'm not sure how their schedule and funding work.

Of course, for PJ we provide you with images that have gone though all of the geometric processing and are projected back to a sphere, but few people seem to use those for some reason.