Optical illusion . . . or . . . Photo evidence of ancient Martian receding lake level?

NASA,JPL & pharmerphil's Photoshop 6 ^ | 1-11-2004 | Phil V. & Socks C.

[RightWhale]

I live on permafrost. There's a lot more to permafrost than you think at first. It's not as interesting and likely to keep you awake as Joe Lieberman, but permafrost is not at all solid like rock. It moves, a process of sublimating and recrystallization under the surface. It could easily form a depression like that in the processed image and do it very quickly, a couple of years.

[Reactionary]

The two images, since they are offset, create the swirling effect when you combine them.

[RightWhale]

a collapse of the surface

Permafrost can do that. There are images of other regions that show something suspiciously like permafrost fields, polygonal patterns. Some of the 'monuments' like the Face could be pingos, although they are more likely weathered outcroppings.

[_Jim]

I'm having difficulty "seeing" the ability of wind to sort stones at different elevations.

On an inclinded and variably inclined (sloped) plane?

Ever seen 'snow rollers'?

What's the chance that different sized material was blown, over time, to accumulate at differnent levels? This process could take years on Mars, and, would not be subject to the usual processes on Earth that would serve to dissolve or wash away such structures ...

[mikegi]

You overlayed the images wrong. Shift the blue one 40 pixels to the left. In the future, pick a easily seen object and align on it. For example, the rock just past the sandy area in the upper left quadrant of the image (the one with the dark seam running NE->SW).

[gitmo]

Heel print from a giant sneaker.

[invoman]

I'm not sure. I just ran it through my paint program myself and got this:

[Salamander]

Let me be the first to hypothesize an ancient land bridge between Mars and Europe.
( I want this on record for when they find the remains of Kennemars Man )

By the by, ever read Patricia Kennealy's "Keltiad" series?

http://www.dragonlibrary.com/scifi/series/Keltiad__Patricia_Kennealy_Morrison.php

Basically it's "Kelts In Spaaaaaaace"

( rofl! )

[the invisib1e hand]

Gad! The place looks like Arizona!

[searchandrecovery]

Obviously my first guess is "land fish". But there's also the possibility that these curved forms might be some kind of lettering - like "Welcome Earthlings", if viewed from a high enough elevation.

[searchandrecovery]

Sorry, as a followup question - if you wear 2 pairs of stereo glasses, do you see in 4 dimensions? That would be cool.

[Phil V.]

The two images are slightly offset.

Yes. That is the nature of sterioscopic/3D images. They are generated from two images taken through two lenses separated several inches. The images "recorded" by the human eye are slightly offset if both eyes stare at "infinity" . . . that is to say, nearer objects will be offset. Depth perception is lost if one looses (closes) one eye. Three D glasses trick the eye into bringing the object together and in the "tiangulation" deph is perceived.

[DaGman]

Looks like excellent work. Very revealing and thought provoking.

[Phil V.]

I know I'm dealing with some "sharp" dudes here, but how about a collapse of the surface caused by an internal force or a meteor hit??

Seismic activity (internal force) could reveal different strata, but one would expect more of a vertical displacement - - - less of a horizontal display.

[ItsForTheChildren]

The cause: global warming; or maybe John Ashcroft.

You know as well as I do that it's Bush's fault!

[Phil V.]

You overlayed the images wrong. Shift the blue one 40 pixels to the left.

It is likely that I do not have the finer points of 3D imagery down pat. But I'm positive that one does not aim to superimpose the two layers so that all objects coincide. That would kill the "tringulation" that the eyes and brain use to see depth. Look at one of NASA's 3D images . . .

The closer objects's double image is farther apart than the more distant. It appears that I have to do more than simply overlay two side-by-side sterioscopic images of different colors.

[mikegi]

Another quick note. I farted around with the images in Paint Shop Pro and found, as I should have realized earlier, that there is no way to properly overlay two images taken from different perspectives.

One cool effect is to align the center of the two images then vary the opacity of layers (there's a slider bar in PSP that gives a live update). When you do this you get that multiangle camera effect that's been popular in commercials and movies (the one where the action is frozen and the perspective rotates around the center).

[Phil V.]

I've done a perspective "transform" in Photoshop to narrow the separation between the farther objects. The same pattern remains in the nearer objects . . . the appearance of "contour lines".

[mikegi]

Perspective transforms don't apply here. I should have been more precise in my previous post: the images come from different *viewpoints*.

Anyway, the "contour lines" are purely an artifact of overlaying the stereoscopic images. To see this, set the opacity of the overlay image to 50% and drag it left and right over the other image. As you do this, the "contours" will move around.

[Phil V.]

I understand that they come from different viewpoints. But if the arrangement of the rocks are "random" then why do "contours" appear on this "ridge" and not in other overlays that I've done from other NASA pics of the surroundings?