Processed Cassini Jupiter Images, Fun with the PDS files Options

[Bjorn Jonsson]

Now that I have downloaded all of the PDS formatted Cassini Jupiter images (and actually all of the Saturn images too) I have been experimenting with processing calibrated versions of them:

http://www.mmedia.is/bjj/misc/css_stuff/im...grnbl1_proc.jpg
http://www.mmedia.is/bjj/misc/css_stuff/im...olor_mosaic.jpg

The first one is simply a global view composed from CB1 (red), GRN and BL1 filtered images with the color balance adjusted to make it more realistic and with some sharpening applied to the image. This is a preliminary version, it looks very bluish at the limb due to Jupiter's rotation (I preferred this to color fringing at the center of Jupiter's disk). Later I plan to fix this by rotating the images in 3D space.

The second one is a reprocessed version of the well known Io transit image but with the addition of the north polar region - since this is a preliminary version some seams may be visible. Later this may turn into a global mosaic. The color balance is also improved. The 'official' image seems to have been composed from CB2, (CB2+BL1)/2 and BL1 filtered images (only CB2 and BL1 images are available). Using CB2 as red makes the belts too reddish if you want whitish zones. To fix this I used a synthetic CB1 image created from a linear combination of the CB2 and BL1 images. Needless to say I also used a synthetic green image.

Now the plan is to do a big cylindrical map of Jupiter followed by an even bigger one of Saturn.

[Guest_Sunspot_*]

Now that I have downloaded all of the PDS formatted Cassini Jupiter images (and actually all of the Saturn images too) I have been experimenting with processing calibrated versions of them:

http://www.mmedia.is/bjj/misc/css_stuff/im...grnbl1_proc.jpg
http://www.mmedia.is/bjj/misc/css_stuff/im...olor_mosaic.jpg

The first one is simply a global view composed from CB1 (red), GRN and BL1 filtered images with the color balance adjusted to make it more realistic and with some sharpening applied to the image. This is a preliminary version, it looks very bluish at the limb due to Jupiter's rotation (I preferred this to color fringing at the center of Jupiter's disk). Later I plan to fix this by rotating the images in 3D space.

The second one is a reprocessed version of the well know Io transit image but with the addition of the north polar region - since this is a preliminary version some seams may be visible. Later this may turn into a global mosaic. The color balance is also improved. The 'official' image seems to have been composed from CB2, (CB2+BL1)/2 and BL1 filtered images (only CB2 and BL1 images are available). Using CB2 as red makes the belts too reddish if you want whitish zones. To fix this I used a synthetic CB1 image created from a linear combination of the CB2 and BL1 images. Needless to say I also used a synthetic green image.

Now the plan is to do a big cylindrical map of Jupiter followed by an even bigger one of Saturn.

Beautiful images.

Where are you finding the Jupiter Images?

[Bjorn Jonsson]

Where are you finding the Jupiter Images?

All of the PDS formatted Cassini images (more than 60,000 !) are available here:

http://pdsimg.jpl.nasa.gov/data/cassini/cassini_orbiter

The Jupiter images taken near closest approach are on volume coiss_1004.

[tedstryk]

I came across a view like the one of Io but with Ganymede. Methinks I must get around to processing it soon

[Toma B]

Bjorn Jonsson what program can I use for wieving *.IMG files???

[Toma B]

by the way those images look great!!!

[djellison]

Toma B - search this forum for ' img2png ' - it's Bjorns tool to convert an IMG file into a 16 bit PNG file - which is readable by just about any program

Doug

[tedstryk]

Here is the best I could do with the ganymede image...the raws are horribly underexposed. It is composed of UV3/P60 + ((GRN/CL1+GRN/CL2+GRN/P0+GRN/P120)/4) + P60/MT2

The images were, as I said, horribly underexposed. Add to that the problem of MT2 making a horrible red filter. Hopefully some more cleaning can make a picture out of this yet!

[djellison]

ted - what range are the source images in?

Doug

[tedstryk]

The sources are:

N1357128733_1.IMG
N1357128799_1.IMG
N1357128865_1.IMG
N1357128931_1.IMG
N1357129012_1.IMG
N1357129078_1.IMG

[djellison]

I think they must have had some sort of 'Red-Filter Awareness' campaign once they left the Jupiter region - nothing..arhghgh

For instance, look at this..
N1357035094_1.IMG
N1357035048_1.IMG

And they made THIS
http://photojournal.jpl.nasa.gov/catalog/PIA02879

???

Doug

[tedstryk]

Perhaps this was done in sympathy with Voyager's red-less ISS

[scalbers]

Might be interesting to redo the Cassini global cylindrical movie of Jupiter in color. The released version was relatively low in resolution, yet the original was at higher resolution judging from one of the still images released. This is the 2-D interpolated movie I'm referring to.

[alan]

Jupiter's Clouds from Cassini
http://antwrp.gsfc.nasa.gov/apod/ap050911.html

[Bjorn Jonsson]

Here is a heavily processed mosaic of the Great Red Spot (GRS) I just finished. It is created from raw (PDS) images obtained close to the time of closest approach:

http://www.mmedia.is/bjj/images/jupiter_ca...grs_caption.jpg

This is a mosaic of several CB2/blue images with the CB1 (red) and green images created using linear combinations of the CB2 and blue images. The effects of varying illumination across the images have been removed, the images reprojected to simple cylindrical projection and then back to perspective projection showing the GRS from directly above, thus showing the true shape of the spot.

The gaps are areas for which the only available data was obtained one rotation (aproximately 10 hours) after the images I used. Due to cloud motions these images cannot be used without 'cheating'.