Posted by
Hemos
on from the interesting-stuff dept.
Alien54 writes: "An interesting article from a German site (but in English!) on the possible correct color corrections for the NASA Mars lander photos is given here and here.
Wait for the photos to load. "
He says, "With the same method [ ] one arrives to 1 also with the graphic data Mars of the Pathfinders (Pic. F) at this colour (Pic. G), whereby however the sharpness of the original pictures by far not here is comparable with the excellent Viking data, there with the Pathfinder mission a information-reducing picture compression (comparable with JPEG) one used."
What method? Arbitrarially increasing the blue and the green because you liked how it looked on the Viking images?
The guy is also woefully misinformed about the amount of water in the atmosphere and the persistance of dust in the atmosphere.
Anomalous: inconsistent with or deviating from what is usual, normal, or expected
-- Anomalous: deviating from what is usual, normal, or expected Canard: a false or unfounded repor
Re:"With the same method"
by
Dienyddio
·
· Score: 2
Do you have any more information on how these calibration charts are used?
Simply looking at a calibration chart through normal camera optics is meaningless. The human brain will try and adjust the colour balance to the earth norm because that is what we are wired for.
What is really needed is a measure of the martian light used to illuminate a white standard across the full UV-Vis-NearIR spectrum. Once that is known and the response of the optics used to take the pictures on mars is known to every frequency in that spectrum you can start to make some colour calibrations.
Using CIE human colour response curves for red, green and blue would then give an impression of how a human on Mars would probably see the colours. To be honest, because this is a function of the iluminating light and because the brain does so much processing based on what it expects to see, it will probably 'look' much like the earth norm.
True colour (for anything other than single wavelength laser) is impossible to define without a human observer, colour is purely a function of our biological make-up. We will see what we want to see.
Re:try the image-creation yourself...
by
rve
·
· Score: 2
The image correction was added, according to NASA, because the blue diode also responded to infra red, thus making the blue signal stronger than it really was. This is not unheard of, it probably means that the second harmonic of the wavelength detected by the blue detector, which falls in the (infra)red part of the spectrum (twice the wavelength) also causes a blue signal. A similar process makes plants green. Plants absorb red light for photosynthesis, but the second harmonic of this wavelength (twice the frequency, or half the wavelength) is absorbed too, making plants white minus lots of red and some blue = green.
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He says, "With the same method [ ] one arrives to 1 also with the graphic data Mars of the Pathfinders (Pic. F) at this colour (Pic. G), whereby however the sharpness of the original pictures by far not here is comparable with the excellent Viking data, there with the Pathfinder mission a information-reducing picture compression (comparable with JPEG) one used."
What method? Arbitrarially increasing the blue and the green because you liked how it looked on the Viking images?
The guy is also woefully misinformed about the amount of water in the atmosphere and the persistance of dust in the atmosphere.
Anomalous: inconsistent with or deviating from what is usual, normal, or expected
Anomalous: deviating from what is usual, normal, or expected
Canard: a false or unfounded repor
This is a pretty cool idea, but I question his methods of determining how much color correction should be applied.
The pictures look great, though they kind of ruin the mental image I (and probably a bunch of people) have of Mars as the "Red Planet".
darren
Cthulhu for President!
(darren)
The image correction was added, according to NASA, because the blue diode also responded to infra red, thus making the blue signal stronger than it really was.
This is not unheard of, it probably means that the second harmonic of the wavelength detected by the blue detector, which falls in the (infra)red part of the spectrum (twice the wavelength) also causes a blue signal.
A similar process makes plants green. Plants absorb red light for photosynthesis, but the second harmonic of this wavelength (twice the frequency, or half the wavelength) is absorbed too, making plants white minus lots of red and some blue = green.