Assembling Voyager movies Options

[Brian Burns]

Hello,

I'm a bit new here - I recently started on a project which I thought would be fun, to assemble movies of all the Voyager flybys. Of course, with 70k+ images, it would have to be automated as much as possible, and the results would be fairly crude. But there's enough information to make some rough black and white and color movies with one segment per target, and eventually combine them all into one movie.

The main task is getting the images properly centered, since the cameras don't point right at the target - there are still some jitters at the moment, so it needs some more stabilization. But in any case, here are some slightly bumpy rides along with Voyager - these are from versions 0.3-0.34 -

Ariel (Uranus)
https://www.youtube.com/watch?v=HeGgH34v8R4

Uranus
https://www.youtube.com/watch?v=0RLGadmvc40

Neptune
https://www.youtube.com/watch?v=HlU2_NOgoew

Assembling a color movie is a matter of combining the images that seem to go together (since it's not explicit in the data) - this is a first attempt at that. There are frames that lack certain channels, so colors are pretty off at points - later it could borrow a nearby image when a channel is missing.

Neptune, colorized
https://www.youtube.com/watch?v=c8O2BKqM0Qc

The goal is to generate the movies with as little manual annotation as possible - there are parts that need it though, like handling images with multiple targets, slowing down the movie at certain points, and turning off the centering at closest approach.

Anyway, just wanted to share what I've got so far - hopefully one day it will be able to make a nice, stable movie of all the flybys, with some appropriate music. Once the code is a little more stable I'll post the project on GitHub - it's written in Python with OpenCV, SciPy, and IMG2PNG.

-Brian

[Astroboy]

I love Voyager movies! People complain about the quality of Voyager images, but they really aren't that bad, especially when freshly processed, and I think they look even better animated. For me, the leftover fuzziness and other imperfections add to the warm, nostalgic charm, and what's almost as cool as a spacecraft carrying a record with Chuck Berry on it to the stars is a spacecraft using an old, 70s TV camera out at the orbit of Neptune. Besides, the Voyager images of the Jovian system, and especially Uranus and Neptune's, are still some of the best available.

If I could offer one suggestion, it would be to think about uploading movies using a single filter and exposure. Sometimes the alternating filter/exposure kind of movies give me eye strain. Really cool stuff you're doing!

I always thought it would be really cool if a crowdsourced project came about that divided all the Voyager images into their respective sequences, animated them in all color combinations available for each sequence while also animating single filter versions, and then made simulated movies out of the mosaics, showing the changing perspective of the target over the course of the mosaic's creation. Then all the movies could be arranged in chronological order and slapped on a Spacecraft Films-style DVD file. Each alternate color or single filter version could be accessed through alternate DVD angles - I've been able to do this myself.

I don't think the Voyager images are ever going to be obsolete. It's a great data set to play around with if you're just starting to get good, like me. Also, even when their scientific usefulness is dried up, they will always be of interest to people who want to see what a particular spacecraft saw at a particular time. That's the big reason I like Voyager movies. You get a unique view from a fantastic spacecraft during a great period in space exploration.

[Brian Burns]

Yeah, some of the mosaics I've seen on this site are really amazing. I still remember the slightly fuzzy images of Io, Europe, and Ganymede I got in the mid 80s - those old NASA 8x10's - and those knocked my socks off.

I initially wanted to make the movies with the RAW images because I like the imperfections also, but it turned out to be too difficult to detect the target across all the different image backgrounds, so I just switched to the calibrated images. It would be possible to write out the target x,y values from the CALIB images to a file but that was just adding more complexity - maybe later.

And I'd thought about limiting some movies to a single filter also, but I hadn't considered the exposure time - maybe you could adjust the brightness depending on that value also. Or try to align the brightnesses across all the different filters in some way.

But yeah, in looking at these Jupiter images, there are tons of 2x2 and 3x3 color mosaics that would be really beautiful - it would definitely need to be crowdsourced in order to incorporate those into a movie. They need to be manually aligned, except for places where there's enough detail for some image stitching algorithms to help. But with the right set up you could have some .csv files describing the alignments which could be hosted on a GitHub project, then people could work on different chunks. Might take a while, depending on how many people were interested. But it would make for really cool HD movies or DVD with the larger mosaics.

And I guess there would be areas of color missing from some of the frames, but you could incorporate prior images into a composite or mosaic also - maybe that would look alright in most cases. As it is now, the colorizing routines manage to group the ogb images together into the different segments of the mosaics, but they're all out of alignment, and of course not put into mosaics.

And it's a good idea to make all the color combos available - I've never tried a disc that had alternate angles. Do you mean you were able to make a DVD that did that?

Yes, the Voyagers were really amazing - and all the planning that went into targeting all these different objects and guiding the craft through the orbits correctly is pretty awesome. And yeah, I think the image quality is fantastic.

[Astroboy]

And it's a good idea to make all the color combos available - I've never tried a disc that had alternate angles. Do you mean you were able to make a DVD that did that?

I've successfully used alternate angles to present an alternate credits option for a movie, so I can easily apply this process to NASA timelapses featuring alternate color combinations. I'm really ecstatic about this and am seriously considering trying it out on the Voyager images.

Another thing that I think would be really cool would be to present animations of each type at a uniform, constant rate a certain amount times the actual speed. For example, zoom movies could be about a day per second, while "standard" movies, like the rotation/volcano/ring/cloud sequences, could be an hour or so per second, and the animations I mentioned in my last post that would present every possible perspective during a mosaic sequence could be a bit under an hour per second. For the "standard" movie type the frame rate would be pretty low at Saturn - Neptune, but it would still allow viewers to compare the rotations and moon orbits, and give people a taste of the reality of how low the data rate was at those targets, which I find interesting at least.

Pretty much every sequence can be made into an animation, including the mosaics as I said, and I find that just lovely. I wouldn't be surprised if a good deal of the mosaics have been done already in still form, but the Voyager image data still seems to be a mostly untapped reservoir of amazingness as far as possible animations are concerned. There are even some pretty conspicuous ring and crescent movies that I haven't seen anywhere online (not counting those YouTube videos that play all the raw frames from an encounter one after the other without stabilization or division of the narrow and wide angles).

[Brian Burns]

Another thing that I think would be really cool would be to present animations of each type at a uniform, constant rate a certain amount times the actual speed.

That's a good idea - I've been slowing the movies down at closest approach so you can see all the details, but it would be interesting to see them at constant rates as well. And I might try putting the date/time at the bottom, and distance from target, though it might be a bit distracting.

Pretty much every sequence can be made into an animation, including the mosaics as I said, and I find that just lovely. I wouldn't be surprised if a good deal of the mosaics have been done already (in still form), but the Voyager image data still seems to be a mostly untapped reservoir of amazingness as far as possible animations are concerned.

Definitely!

And I really like the closeups of Jupiter's clouds - they're kind of mesmerizing. Especially the way they are autocolorized at the moment - the images are mostly red/purple, or blue, or green. E.g. here's one that's clearly not aligned, but I like the colors - and there are tons of these -

http://imgur.com/a/qmtA4

I've been trying to get the movies more stabilized lately - the Hough circle detector isn't sensitive enough and results in jitters, even for extremely similar frames. I was experimenting with ECC image alignment (http://www.learnopencv.com/image-alignment-ecc-in-opencv-c-python/) to see if it could help, with mixed results - I'll have to pick it up again tomorrow. I did try Windows Movie Maker's stabilization just to see what it would do, but the results were actually worse than without it.

Here is what the program does at the moment, more or less -

CODE

    Voyager commands

      vg download <volnums>             - download volume(s)
      vg unzip <volnums>                - unzip volume(s)
      vg convert <volnums>              - convert IMGs to PNGs
      vg adjust <volnums>               - adjust/rotate images
      vg center <volnums>               - center images
      vg composite <volnums>            - create color images
      vg target <volnums>               - copy images into target subfolders
      vg clips bw|color [<targetpath>]  - create bw or color movies of flybys
      vg movies                         - combine clips into movies
      vg list                           - show status of local datasets

    where

      <volnums> = 5101..5120 Voyager 1 Jupiter
                  6101..6121 Voyager 1 Saturn
                  5201..5214 Voyager 2 Jupiter
                  6201..6215 Voyager 2 Saturn
                  7201..7207 Voyager 2 Uranus
                  8201..8210 Voyager 2 Neptune
                  (ranges and wildcards like 5101-5104 or 51* are ok)

      <targetpath> = [<system>]/[<spacecraft>]/[<target>]/[<camera>]
      <system>     = Jupiter|Saturn|Uranus|Neptune
      <spacecraft> = Voyager1|Voyager2
      <target>     = Jupiter|Io|Europa|, etc.
      <camera>     = Narrow|Wide

    e.g. vg clips color //Triton

    You can also add `-y` to a command to have it overwrite any existing data.

I'm trying to get it so people could work on different volumes and target sequences through GitHub, using csv files for the database - e.g. for the centering information, composite images, movie sequences, frame rates, etc.