T or E

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Trinket</i>
<br />Every Image ever released has gone thru the JPL Image muting and distortion process..<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">I'm no fan of JPL, but that is just nonsense. They'd be sacked in a heartbeat if they messed with the data. Every spacecraft image is available in raw, completely unprocessed format for anyone who wants it that way. And the processed images follow the formula posted, which uses legitimate image processing techniques except where otherwise noted. The three 1998 Cydonia images were a special assignment by NASA and had their own web site with the recipe used posted there. The raw, unprocessed data is also available, which is how we know what they did to the press release image.

It is part of NASA's charter that all its science data be freely available to the world. -|Tom|-

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Trinket</i>
<br />I dare you to show me an uncropped image that does not have both areas to bright and to dark in the same Image..<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">The CCD camera on board the spacecraft has a much broader range of brightness than the human eye. That is why we must all do image processing to bring out specific features in the images by changing the brightness and contrast ranges to those that the human eye would see if it were at Mars.

So that point is just a matter of education, not tampering. -|Tom|-

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Trinket</i>
<br />Please describe to me the process at which this highlighted area
will return to clarity..<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">Here's the view using the new "equalize" process:

Clearly, these areas are overexposed, as would happen to any photo taken with too long an exposure hoping to bring out faint details. Do you find something suspicious about this?

Interestingly, those small, black squares appear to be real interruptions of the high-reflectivity material, not products of pixelation. This probably hints at the "mining" hypothesis. -|Tom|-

<i>Originally posted by Trinket</i><blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">Please describe to me the process at which this highlighted area
will return to clarity.
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
I'm pretty sure I understand your question. You want to know how to make sense of the shading in the area you highlighted, how to reconcile it in your mind against the suspicion that it has been "tampered with." It doesn't seem logical, or as Tom would say, "intuitive." We spent a considerable amount of time considering this question, so I'll try to answer it.

First there is the light reversal problem as we mentioned above. Second it seems very bright, almost white in the lighted areas, and it's hard to imagine the way the shadows "should look." It turns out that this image was taken at 7AM (from the MOC acquisition parameters for SP243004). The incidence angle of the Sun is 78.4 degrees. That puts the angle of the Sun from the horizon at 11.6 deg. I believe the result is a reflective glare between the Sun, the slope of the walls of the trench, and the camera. Rich thinks the material composition of the feature is also a factor adding to the glare, and that may indeed be the case. Third, the resolution of the SP2 image is fairly low, only 7.29 m/p.

So I think the combination of glare you're seeing, coupled with the poor resolution, and the light inversion, all add up to an image that is hard to reconcile in your mind with how it "ought to look." But we don't see any evidence of tampering at all.

We will try to provide more description of what we think we see as we proceed with this post.

Neil

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Trinket</i>
<br /> Please describe to me the process at which this highlighted area will return to clarity..<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">

Trinket,

I think I understand why this feature looks so strange. Believe me, I had the exact same impression you did. As a matter of fact, if this topic had a sub-title, I think it would be: "Why is it so shiny?"

I have a theory about this. In part, I believe we're dealing with a highly reflective material, but I also think this is a function of the topography.

Here is the image strip again. This one is rotated so that I could crop a thin strip that covers the whole length without it being 6MB (this one's less than 2MB). This is still raw data. My purpose was to retain the relative reflectivity over the whole length of the strip.

{Image deleted temporarily} T%20or%20E/SP243004_rot_c2.gif

Now here is what the histogram of this cropping looks like:

{Image deleted temporarily} T or E/SP243004_rot_c2_Hist_c1.JPG

You'll notice that the peak is fairly close to the middle of the grayscale, and that the rest of the pixels are brighter, with some being 100% reflective. So, for most of the strip, the camera did a pretty good job, it's just that the top of the strip was significantly more reflective. This is just a wild guess, but I think it's possible that they didn't compensate for the changing altitude of the surface, relative to what they had been doing prior to that. My suspicion would be that the images farther south east(away from the mountain) would have been perfect (i.e., the images taken just prior to this).

If you go back down about halfway and look at this image again, at one of those "fingers" cutting through the triangular area, you'll notice that they are very reflective too, there's just not much of it:

{Image deleted temporarily} T or E/Fig%202.jpg

The reason why it's so shiny, aside from the fact that it's highly reflective, is that the sun is shining directly at it.

Which brings me to the point of this post. The top portion of the strip, including (especially) the "cross" of the "T" is being hit by the sun on a more direct angle. In other words, the terrain must be sloped downward from left to right. Couple that with the fact that there may be a greater concentration of whatever it is that's making it reflective.

Now, if I can just figure out how to read the MOLA data, I think I can prove that. If "prove" is too strong a word, then maybe I can produce some corroborating evidence.

rd

<i>Origially posted by rderosa</i><blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">The reason why it's so shiny, aside from the fact that it's highly reflective, is that the sun is shining directly at it.
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">

In this uncropped version of the same context image shown above, the brightest glare is coming from the plateau above the escarpment and from some outcroppings to the east of the T or E, and not from the T or E itself. This indicates that the angle of the Sun (which is coming from the west in this image) is a significant factor in what features produce a glare. I would also hazzard a guess that in the MOC acquisition parameters, the Gain and Offset modes were set for less bright lighting conditions, and so the T feature (in SP2, first image shown in this post), and the fact that its trenched out sloped walls reflected the low angle of the Sun more directly, produced an anomolous glare, as seen in the Histogram analysis above. Notice that the small rock outcroppings in SP2, to the left of the T, also produce a strong glare, but there is much less area reflected as compared with the T itself.


Neil