IMAGE PROCESSING GALLERY
For those of you who have contributed – thank you! Your labors of love have illustrated articles about Juno, Jupiter and JunoCam. Your products show up in all sorts of places. I have used them to report to the scientific community. We are writing papers for scientific journals and using your contributions – always with appropriate attribution of course. Some creations are works of art and we are working out ways to showcase them as art.
If you have a favorite “artist” you can create your own gallery. Click on “Submitted by” on the left, select your favorite artist(s), and then click on “Filter”. For other tips about the gallery click on the “Gallery Organization” tab.
We have a methane filter, included for the polar science investigation, that is almost at the limits of our detector’s wavelength range. To get enough photons for an image we need to use a very long exposure. In some images this results in scattered light in the image. For science purposes we will simply crop out the portions of the image that include this artifact. Work is in progress to determine exactly what conditions cause stray light problems so that this can be minimized for future imaging.
The JunoCam images are identified by a small spacecraft icon. You will see both raw and processed versions of the images as they become available. The JunoCam movie posts have too many images to post individually, so we are making them available for download in batches as zip files.
You can filter the gallery by many different characteristics, including by Perijove Pass, Points of Interest and Mission Phase.
A special note about the Earth Flyby mission phase images: these were acquired in 2013 when Juno flew past Earth. Examples of processed images are shown; most contributions are from amateurs.
The spacecraft spin rate would cause more than a pixel's worth of image blurring for exposures longer than about 3.2 milliseconds. For the illumination conditions at Jupiter such short exposures would result in unacceptably low SNR, so the camera provides Time-Delayed-Integration (TDI). TDI vertically shifts the image one row each 3.2 milliseconds over the course of the exposure, cancelling the scene motion induced by rotation. Up to about 100 TDI steps can be used for the orbital timing case while still maintaining the needed frame rate for frame-to-frame overlap. For Earth Flyby the light levels are high enough that TDI is not needed except for the methane band and for nightside imaging.
Junocam pixels are 12 bits deep from the camera but are converted to 8 bits inside the instrument using a lossless "companding" table, a process similar to gamma correction, to reduce their size. All Junocam products on the missionjuno website are in this 8-bit form as received on Earth. Scientific users interested in radiometric analysis should use the "RDR" data products archived with the Planetary Data System, which have been converted back to a linear 12-bit scale.
Juno's Perijove-04 Jupiter Flyby, Revised Reconstruction from JunoCam Images
On February 02, 2017, NASA's Juno probe successfully performed her Perijove-04 Jupiter flyby.
From JunoCam's raw image data, and SPICE navigation data, the movie reconstructs the two hours and 15 minutes from ISO time 2017-02-02T12:00:00.000 to 2017-02-02T14:15:00.000 along Juno's trajectory in 125-fold time-lapse.
JunoCam is the Education and Public Outreach camera of NASA's Juno spacecraft. Juno's major science objective is looking beneath Jupiter's impressive cloud tops. In addition, JunoCam gives us a first close look at Jupiter's polar regions at wavelengths of visible light.
The reconstruction makes use of the 13 raw JunoCam Perijove-04 RGB images #97, #99 to #109, and #111.
In steps of five real-time seconds, one still images of the movie has been rendered from at least one suitable raw image. This resulted in short scenes from one to about 13 seconds.
Playing with 25 images per second results in 125-fold time-lapse.
Resulting overlapping scenes have been blended using the ffmpeg tool.
In natural colors, Jupiter looks pretty pale. Therefore, the still images are approximately illumination-adusted, i.e. almost flattened, and consecutively gamma-stretched to the 4th power of radiometric values, in order to enhance contrast and color.
There are some considerable time gaps between consecutive raw images. This required reprojections of portions of raw images close to Jupiter's limb to a perspective as if the camera would have been above this surface area of Jupiter. This resulted in a degraded quality of some portions of the movie.
The movie starts with a resonstructed in-bound sequence approaching Jupiter from north. Then the orbit approaches Jupiter down to an altitude of about 4,000 km near the equator.
This is followed by a transition into the outbound orbit, during which Jupiter's south polar region comes into view.
Rendering the still images of the movie took about four days on one up to three virtual CPU cores running in parallel.
The rendering software for the stills is proprietary. Trajectory data were retrived from SPICE kernels with the SPICE/NAIF tool spy.exe. from For combining stills to movie files, the tool ffmpeg has been used.
Blending may result in feature-doubling in overlapping scenes due to reprojection inaccuracies, and to some fast shifts of quality and/or color.
Most repetitive bright and dark camera artifacts are patched. Due to the intense radiation near Jupiter, some additional bright pixels occured, visible in the stills the movie is rendered from, at least. Those aren't patched in this animation.
In rarer cases, lightnings on Jupiter might also show up as bright pixels.
Sometimes, the edges of the raw images show up as black triangular areas in some corners of the movie rendition.
During blending, features may be doubled due to alignment inaccuracies of the blended scenes.
Some of the very close-ups show block artifacts as a result of lossy compression within the camera, which has been necessary due to limited storage.
Cloud motions are probably too tiny to be perceptible from this distance, and within the short time.
Any residual issues in the movie are due to imperfect image processing.
The movie may nevertheless provide you an idea of Juno's Perijove-04 flyby.
JunoCam was built and is operated by Malin Space Science Systems in San Diego / California / USA.
Many people at NASA, JPL, SwRI, and elsewhere have been, are, and will be required to plan and operate the Juno mission.