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-05 Jupiter Flyby on 2017-03-27, Reconstructed from JunoCam Images and SPICE Data
On March 27, 2017, Juno performed her Perijove 05 flyby (PJ-05) with all instruments on, including JunoCam.
JunoCam images covered all Jupiter latitudes, but some parts only with very acute angles.
This computer animation uses the JunoCam images of PJ-05 as textures, and SPICE trajectory data in order to reconstruct the flyby as seen from Juno's perspective.
For each still image, the according raw JunoCam image has been used directly to reconstruct Jupiter's appearence from the respective trajectory point.
The pointing is specific to this animation. In reality, Juno is rotatating once each 30 seconds.
The movie is 125-fold time-lapsed relative to real time.
The movie consists of 2703 still frames, reconstructed from the 16 Perijove-05 images #99, #100, #101, #102, #104, #1ß5, #106, #107, #108, #109, #110, #111, #112, #113, #115, and #116.
Brightness flickering, and other brightness changes in the movie are processing artifacts.
The movie is almost completely illumination corrected with a heuristic method, and stongly enhanced, with gamma=8 relative to square-root encoding.
But some of the illumination was added again, after enhancement, in order to obtain a better three dimensional appearance.
Brightness is adjusted for each still frame individually by using the 99% percentile as a reference value for brightness correction.
The simulated field of view is 80x45 degrees. The projection of the still images is cylindrical/spherical.
The stills have been calculated from the raw JunoCam images and SPICE data using a proprietary software developed for JunoCam image processing.
The stills have been assembled to a movie with ffmpeg.