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Originally Posted by JonClarke
The primary image is low in contrast, but this does not mean to say that they selectively removed. Given the hazy atmosphere and the high sun angle the image is naturally and inevitably lacking in contrast with small shadows.
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Jon, it doesn't make sense to attempt to use circumstances on Mars, e.g. haze and sun angle, to explain changes which occurred _after_ the image was received on Earth.
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The effect of the processing has been the opposite to what you claim. A low contrast image has had that increased.
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You seem to be making the mistake of trying to view the "raw" image without first normalizing its contrast. The human visual system isn't well adapted for viewing images composed of pixels whose values are crowded together in the middle of the histogram. If you want to understand the processing that was applied to the image, you'll need to normalize the contrast of the raw image, before comparing it visually to the processed image. (In fact you won't need to normalize the contrast yourself, because I've already done it for you, in all the images that I've uploaded.)
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Note that using the expressions "aggresively suppressed" and selectively eliminated" implies deliberate distortion by the people do did the processing.
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The word "selectively" bears no such connotation. Non-human processes can be selective in their effects. However, I can understand how you could misinterpret my use of the word "aggressively." You may consider that word retracted, and replaced with "severely."
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Sorry, I don't find the animation useful. It's of too small an area, the extact context of each sub part is not clear,
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If the cropped version (before-after-slope.gif) shows too small an area for you, you can look at the uncropped version (before-after.gif). They are the same animation, except that one has been scaled down 50%, while the other has been left at 100% but cropped and highlighted.
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and it is not obvious which processed frames have beeen used.
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The first frame (in both animations) is from cydonia1.tif, the image that was returned by the spacecraft (with left/right inversion corrected, and contrast normalized). The second frame is from cydonia1c-s.gif, the image that was used in the press release. I've applied a simple streak removal algorithm to both frames.
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What would be better a side by side comparison of the different images with labels highlighting the differences between them.
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I'm attaching for you a side by side comparison, with a highlight showing the exact location where "before-after-slope.gif" was extracted. The left image is from the spacecraft, the right image is from the press release. Minimal processing has been applied, as in the two before-after animations, described above.
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Unfortunately your "forensic image analysis" is simply wrong. Your "reconstructed" a processing methology has no relation to what was actually used
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No, my analysis is not wrong. Whether they knew it or not, they used the "catbox convolution" that I described in my first two articles in this thread.
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and your claim that contrast was suppressed is contrary to the simple fact that contrast enhanced. In faact, almost nothing can be seen in the raw image.
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Almost nothing can be seen, because you're trying to view the "raw" image without first normalizing its contrast. Don't try to do that; your human visual system simply isn't equipped for that task.
This is because all three (MIPL and Parker and MSSS) normalized the contrast. You need to do the same.
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Originally Posted by Bad. Guardian
Most of my followups in this thread have just been clarifications for people who are confused about the basic facts, e.g. which image was returned by the spacecraft, and which image was used in the "catbox" press release.
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Not confused at all as to which basic image was being referred to, MOC2-41.
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That clause of that sentence was meant to refer to someone else, not to you. I apologise for the misunderstanding.
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Let's see, so far you have been show links with the following facts:
Observing conditions were well below par.
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True, but irrelevant. Observing conditions on Mars cannot explain changes which occurred _after_ the image was received on Earth.
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The actual processing of the image used by MIPL, MSSS and Tim Parker
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The published description of MIPL's processing was vague; it wasn't detailed enough to allow outside people to replicate the effect exactly. My description of one part of their processing (the part that "flattened" the landform) is 100% explicit; it includes enough detail (even source code) to allow anyone to replicate the effect exactly.
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The original, image, washed out because of the poor observing conditions, was processed to enhance contrast enhanced, not supress it.
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All images are contrast-normalized before publication. The "catbox" image, however, had another very important processing step, which selectively _suppressed_ all large-scale brightness variations, applied to it before its contrast was normalized.
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Since you don't appear to have taken any of these facts on board,
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I know the facts, and have known them since before I initiated this thread.
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I advise you to be careful who you call clueless, especially when passing judgement on people and groups of the calibre of the MIPL, Tim Parker, and MSSS.
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Thank you for your advice. I stand by my use of the word "clueless" in reference to that particular image.
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Note that the different processed versions of the same image were all available on the same day. That's honest, showing different ways of processing the same data and letting people shose which one they prefer.
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That is well and good. But one of those images, which was very widely published in mass media around the world, was extremely deceptive. Its creation and dissemination were Bad Astronomy. The failure to retract it was Bad Astronomy.