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Posted by: Fred Feb 5 2005, 07:49 PM

On the DISR http://www.lpl.arizona.edu/%7Ekholso/data.htm, there are new links to 5 anaglyph images, but the links are broken. I can't find the images in any of the directories of the webpage either. Does anyone know of anywhere else these images might be available?

Posted by: CosmicRocker Feb 5 2005, 10:17 PM

I was eagerly looking for them myself, since I have been trying to make anaglyphs from the DISR images with little success for quite some time now. The URLs there are bad, but I found the images after a little URL editing.

http://www.lpl.arizona.edu/~kholso/images/bashar/StereoA.jpg
http://www.lpl.arizona.edu/~kholso/images/bashar/StereoB.jpg
http://www.lpl.arizona.edu/~kholso/images/bashar/StereoC.jpg
http://www.lpl.arizona.edu/~kholso/images/bashar/StereoD.jpg
http://www.lpl.arizona.edu/~kholso/images/bashar/StereoE.jpg

However these are not anaglyphs, but stereo pairs.

Posted by: djellison Feb 6 2005, 01:29 PM

AKK - those are NOT anaglyphs

Anaglyph: A moving or still picture consisting of two slightly different perspectives of the same subject in contrasting colors that are superimposed on each other, producing a three-dimensional effect when viewed through two correspondingly colored filters.

They're stereo pairs ( and very bad stereo pairs as well, I couldnt make anything from them at all )

This was the best I could do in making proper anaglyphs from them






Doug

Posted by: slinted Feb 6 2005, 02:48 PM

I found what I think makes a decent pair between High res frames 415 and 448, here they are cropped to the overlapping region in view, and doubled in size (cubicly interp'ed). Please excuse if these aren't of the quality many folks are used to, I'm new to making anaglyphs.
I'm trying my best not to impart any artificial stereo effects.

Posted by: Gsnorgathon Feb 7 2005, 02:46 AM

Doug - I am so glad to hear you say you couldn't make anything out of those (alleged) stereo pairs. I stared at 'em until I was bug-eyed and couldn't make anything out at all.

Posted by: CosmicRocker Feb 7 2005, 05:41 AM

Yeah, I can't imagine why they are calling them anaglyphs. The posted images are really poor stereo pairs, and I couldn't see any convincing relief viewing the pairs side by side, even with a stereoscope. The left and right images weren't even scaled the same, and they were rotated with respect to one another. I'm not sure why they would release images like those and suggest people could see depth in them.

I tried rescaling and rotating them into alignment as best I could, and then made anaglyphs from them. Taking a lead from Doug, it seeemed to me that some of the pairs needed to be rotated significantly before I could see any stereo affect.

I really am convinced that some DISR image pairs do contain some 3D information. There seem to be some distortions in the images that I have not been able to get rid of, so my anaglyphs are less than perfect. I do think I am seeing a bit of relief, but these are not the kind of anaglyphs that jump out at you. We may have to wait for the mission team to properly process the pairs before we see anything convincing.

I am trying to attach some of my anaglyphs to this message, but when I attach one, it appears to upload with my message, but it does not appear in my preview. Any help regarding that would be appreciated. I have a small amount of server space where I could post them, but I wouldn't be able to leave them there forever. I know, there are free image hosting sites, but I would prefer not to go that route. I would just like to learn how to make file attachments work here.

Posted by: BruceMoomaw Feb 7 2005, 06:15 AM

There's certainly some stereo information from Huygens' images -- they've been quite firm in saying that this has allowed them to calculate the height of the central ridge near the "shoreline", from which the arroyos on both sides drain down, at about 100 meters. Since it's only 300 meters or so wide, this is quite a slope.

Posted by: volcanopele Feb 7 2005, 08:27 PM

I've posted on my blog about the topo graphic features I see in these stereo pairs.

In addition, I've outlined features in StereoA and D that I think are topographic highs.

• http://pirlwww.lpl.arizona.edu/%7Eperry/StereoA.outline.jpg
• http://pirlwww.lpl.arizona.edu/%7Eperry/StereoD.outline.jpg

Posted by: CosmicRocker Feb 9 2005, 05:24 AM

Well, I've put a lot of work into these things and was hoping to achieve better results, but this is what I have been able to do so far. I really think Doug was onto something by rotating the images. I could see no convincing topography in the A and D pairs until I rotated them.

After rotation, I can easily discern the same topography in both the side-by-side stereo pairs and the anaglyphs. What I see has some similarities to that which was highlighted by Volcanopele in his images, but it differs significantly in detail.

In these anglyphs, I have rescaled and rotated the left side to better match the right side. Those adjustments were less than perfect, but I think they have helped. As I mentioned previously, there seems to be some kind of distortion that I don't understand and have not been able to remove so far.