My Ganymede mosaic, Made by hand, around 1999 |
My Ganymede mosaic, Made by hand, around 1999 |
Oct 18 2010, 03:36 AM
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![]() Junior Member ![]() ![]() Group: Members Posts: 49 Joined: 9-October 10 From: Victoria, BC Member No.: 5483 |
This is a colour global view of Ganymede, taken using Orange, Blue and Violet images (in the RGB channels respectively) from Voyager 2. I made it using ISIS around 1998 or 1999, it's an orthographic reprojection of a mosaic of the antijovian hemisphere. I don't think I stretched the histograms in the component images at all.
I wish I could remember what specific images I used (I'm reasonably sure that I was using the images that start around C2063105). Annoyingly I can't find my notes on it - I'm lucky I actually managed to find the image itself! I do remember that I had to manually match the images - I didn't have IDL or any of that other fancy stuff, working in a UK university that didn't have the funds to buy it. I looked at each adjacent/overlapping image pair in a given filter, looked for a minimum of three match points between the images, and noted down the pixel locations for all of them in a little black book and in a text file that ISIS would read, and then did that several times for each overlapping image pair - it took weeks to find all the match points, and sometimes ISIS would still just not match the darn thing properly and so I had to go back and find different ones. As it is it nearly broke the computer I used to make it (which of course was great for the time and completely laughable by modern standards), and I think the end mosaic (in original .cub format) was over a gigabyte in size! I'd have to leave the ISIS script to take it from level 0 to level 4 running overnight and hope it all worked. I also used updated SPICE data for Voyager that I got from Tim Colvin at RAND Corporation (that IIRC wasn't in ISIS at the time). The resolution of the mosaic is 2 km/pxl. Probably not awesomely useful for science, but I'm pretty proud of it considering the effort it took to make it - hope you like it |
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Oct 19 2010, 06:26 PM
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![]() Bloggette par Excellence ![]() ![]() ![]() ![]() Group: Admin Posts: 3968 Joined: 4-August 05 From: Pasadena, CA, USA, Earth Member No.: 454 |
Since the scripts are just text files and shouldn't take up too much space, I say post 'em. I have fantasies that I'll get back into using ISIS for image processing but I'll have to get myself a Mac first...
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EDG My Ganymede mosaic Oct 18 2010, 03:36 AM
DrShank >>I wish I could remember what specific imag... Oct 18 2010, 01:35 PM
tedstryk One of my Ganymede mosaics uses that set with wide... Oct 18 2010, 04:28 PM
EDG Only 18 images? Seemed like a lot more! (maybe... Oct 18 2010, 06:17 PM
ugordan QUOTE (EDG @ Oct 18 2010, 08:17 PM) So ba... Oct 18 2010, 06:41 PM
EDG Very nice! Thanks for doing that, I've of... Oct 18 2010, 07:23 PM
DrShank its about as close to natural color (at high resol... Oct 18 2010, 11:46 PM
EDG Hooray! I just managed to find all my old Gali... Oct 19 2010, 08:10 AM
tasp Thanx!! Oct 19 2010, 05:32 PM
EDG QUOTE (elakdawalla @ Oct 19 2010, 11:26 A... Oct 19 2010, 07:10 PM
Bjorn Jonsson Great mosaic, especially when keeping in mind that... Oct 19 2010, 06:48 PM
EDG QUOTE (Bjorn Jonsson @ Oct 19 2010, 11:48... Oct 19 2010, 07:11 PM
EDG This is the global mosaic of Ganymede's traili... Oct 19 2010, 07:17 PM
EDG I was going to start a new thread for this but I t... Oct 20 2010, 07:37 AM
tedstryk Cool. That looks like the set I used in this one.... Oct 20 2010, 05:20 PM
EDG QUOTE (tedstryk @ Oct 20 2010, 10:20 AM) ... Oct 20 2010, 05:52 PM
ugordan EDG, any idea why you have color shifting in the 3... Oct 20 2010, 06:20 PM

EDG QUOTE (ugordan @ Oct 20 2010, 10:20 AM) E... Oct 20 2010, 06:47 PM

ugordan QUOTE (EDG @ Oct 20 2010, 08:47 PM) Are y... Oct 20 2010, 06:51 PM

EDG QUOTE (ugordan @ Oct 20 2010, 11:51 AM) Y... Oct 20 2010, 08:34 PM

tedstryk I didn't notice that problem. Oct 20 2010, 08:37 PM
tedstryk I am trying to find my notes...I did that image th... Oct 20 2010, 07:27 PM
EDG To correct the blurriness (aesthetically anyway), ... Oct 20 2010, 07:40 AM
EDG The next attempt is actually as close to true colo... Oct 20 2010, 07:49 AM
ugordan QUOTE (EDG @ Oct 20 2010, 09:49 AM) All t... Oct 20 2010, 08:13 AM
tedstryk QUOTE (ugordan @ Oct 20 2010, 09:13 AM) P... Oct 20 2010, 05:22 PM
EDG And finally, just for kicks I tried an OGU image (... Oct 20 2010, 07:52 AM
EDG I've found the scripts for the Voyager 1 mosai... Oct 21 2010, 05:24 AM
ngunn Titan has veiled wonders and Io suppurates, but to... Oct 21 2010, 10:35 PM
EDG QUOTE (ngunn @ Oct 21 2010, 03:35 PM) Tit... Oct 22 2010, 07:06 AM
Decepticon EDG Have you done other moons?
Europa maybe? Nov 23 2010, 05:59 AM![]() ![]() |
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