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The Real Reason why Spirit Only Sees Red
use_compress writes To produce a color photograph, the rover's panoramic camera takes three black-and-white images of a scene, once with a red filter, once with a green filter and once with a blue filter. Each is then tinted with the color of the filter, and the three are combined into a color image.
In assembling the Spirit photographs, however, the scientists used an image taken with an infrared filter, not the red filter (NYTimes, Free Registration Required). Some blue pigments like the cobalt in the rover color chip also emit this longer-wavelength light, which is not visible to the human eye."
The reason being that the science gets better results using th e IR filter than if the red filter were used... At the moment, despite great public interest, the science is more important... that IS what it's there for....
Simon
Physicists get Hadrons!
'Aha! So that's why they don't see little green men...' - at last, the dream of aliens living on Mars is alive again.
How the Red Planet Came Down With the Pink Blues
They mention slashdot.org by name.
Could this be some sort of revenge?
Can anyone explain why 3 separate B/W images are taken? If it is because of bandwidth... 3 grayscale images weights (more or less) like one color image ... so why B/W and filters?
------- The last Sig. got fired.
It's a good job the pictures aren't coming back with a blue tint, or lynch mobs would be turning up at NASA HQ.
If I seem short sighted, it is because I stand on the shoulders of midgets
So when are we going to have the technology to send _colour_ cameras to Mars?
I've seen them in some very expensive shops, so I'd have thought NASA would be able to shrink one down to the size of a football or so.
The Slashdot Paradox: "100% Overrated"
I tried showing them to my pet bull and he immediately became bad-tempered and generally unpleasant to be around of. He's much fonder of the Neptune shots from Voyager really...
"A door is what a dog is perpetually on the wrong side of" - Ogden Nash
On the panoramic picture: We goofed. It should not have been that red.
The other photographs are taken with the infa-red instead of visible red filter. Iron dominated the visible red spectrum. To allow a better analysis of the compounds found infa-red light is used instead.
<joke>No conspiracy here. Move on.</joke>
the_crowbarHave you read the Moderator Guidelines
They're taking images through blue, green, red and infrared filters. The color shift problem in the publicly released images is because they're blending in the infrared shot instead of the red shot, right? Why don't they just release the RGB images as well as the iRGB? They have all the images after all--why waste press conferences explaining the differences or lack thereof when they could just give us the pictures?
Reminds me of the Gameboy Camera Color Project: http://www.ruleofthirds.com/gameboy/
I think the ones in CompUSA are a tad sensitive to the extreme temps on Mars.....
Because a standard 4 megapixel camera would freeze on Mars.
- Kaos games and encryption systems developer
Some blue pigments like the cobalt in the rover color chip also emit this longer-wavelength light, which is not visible to the human eye."
If it's a *blue* pigment, why does it emit a *longer* (i.e. infrared) wavelength?
The human eye's color vision is a poor scientific instrument. It can be easily fooled.
Mea navis aericumbens anguillis abundat
Quite possibly because it wouldn't survive the conditions on Mars. Or on the way there. Try deep-freezing your digital camera, then put it in a vacuum chamber, then in a really dusty sandbox, and finally subject it to a potentially lethal (for a human) dose of radiation, and see if it still works. Oh, and don't forget simulating the landing; heat it, vibrate it, and toss it on the ground.
Disclaimer: I wasn't there. I don't know exactly how the poor thing was treated. I'm not a member of the PETC (People for the Ethical Treatment of Cameras).
This signature is not in the public domain.
Since nobody else has yet, the registration free partner link: http://www.nytimes.com/2004/02/10/science/space/10 COLO.html?ex=1076994000&en=a6c9abc6b269678b&ei=506 2&partner=SL4SHD0T
Unfortuantly I can't find any references as to the loss{y|less}ness of the compression used
Music is everybody's possession.
It's only publishers who think that people own it.
Fuck Beta
~John Lenno
Atleast I think this is what you were referring to... :-/
---
Any man who can drive safely while kissing a pretty girl is simply not giving the kiss the attention it deserves. -- AE
because that 4 megapixel camera from comp usa is a total piece of crap compared to the 1 megapixel B&W camera on the rover.
I have a old 2 megapixel digital camera that will beat the Best 4-6 megapixel consumer camera you can buy today. because of optics and the design of the CCD. (mine is a TRUE 2 megapixel whereas almost ALL camera's today sold as a 4 megapixel are really a 1.3 megapixel camera as you need 3 pixels for each photographed pixel.. (I.E. one for red,green and blue.)) plus the resolution of each color captured is vastly different, green usually being the best resolution while blue suffer's the most..
Nasa is not about to send the really low grade crap that is available to the cunsumer to another planet. they sent the real deal.
I suggest you actually learn about digital photography and why consumer grade "cameras" are utter junk.
Do not look at laser with remaining good eye.
I'm scratching my head on this one, i said, or i thought i said something funny. It was funny at the time because I was watching the first episode of The Hitchhikers guide to the galaxy. My interpretation of its humour hasn't come over well then has it? What if i said the joke was harmless, no, mostly harmless, do i get modded +5 funny now?
Jonathanjk.com
maybe you should try taking infrared photos?
most of the digital cameras on the market dont have countermeasures to prevent IR exposures, so feel free to experiment with various infrared-transmitting, deep red and light red filters.
from my non-scientific experience, ultraviolet photos of rocks is more interesting than infrared.
So tell me... where did you get a 'foveon' chip several years ago?
On top of that... 3 colors multiplied by 2 megapixels = the equivalent of 6 'consumer' megapixels.
Now... Current CMOS / CCD sensors on consumer cameras are up to 8 megapixels, with more professional cameras hitting 14 (Kodak for example).
And that's only in the D-SLR style. There's also Medium-format backs which have up to 20 something megapixels in resolution.
So... Please explain to me how your 2 megapixel sensor (which would btw invalidate all Foveon technology) surpasses these much higher res devices.
Thanks
I suggest you see the post for what it was meant for... a joke!
Jonathanjk.com
The martian crab http://homepage.mac.com/thomasmcgee/ I know, I know, go ahead, mod me off topic. The truth is out there. Would anyone like to start a petition that requests NASA to try to get one more photo of this thing before they drive away?
Yeah, and then why didn't the fools just toss it in a tupperware container and duct tape the lot to a couple of cheap firework rockets and light the blue touch paper. I mean come on, how complicated can it be?
Art Buchwald has the whole scoop here.
http://science.slashdot.org/article.pl?sid=04/01/0 9/1724246&mode=thread&tid=134&tid=152&tid=160&tid= 185
Not to be nagging, but you forgot to mention the launch. The spacecraft suffers a lot of shaking and vibrating through launch. Not just the acceleration caused by the rocket, but also (and maybe even worse) the vibrations caused by the noise of the rocket engines. Part of the testing is actually done with huge loudspeakers
karma capped
On top of that... 3 colors multiplied by 2 megapixels = the equivalent of 6 'consumer' megapixels.
That was his point. The common 4 megapixel cameras are actually only 1.3 per color.
Regardless, megapixel count is hardly the most important aspect of a digital camera. The lens matters far more, as does the spacing and quality of the pixels. Really, NASA has a very interesting article on the topic.
Exactly
Jonathanjk.com
They're not utter junk, they're just consumer-grade, is all...
Come on, give it up, that's
AHA!! That's why it had that problem. It stopped and was waiting for the traffic light to turn green.
-
Roses are #FF0000, Violets are #0000FF, find / -name '*base*' |xargs chown -R us && mv zig greatjustice
Manufacturer? Model?
I've often wondered exactly how rigid the "400-700nm is visible" rule applies. We know that some animals can see infra-red and ultra-violet. But just how well-defined is the wavelength range for human beings? I mean, our bodies are different shapes and sizes, our voices have different pitches, our ears have varying ranges, some of us are allergic to certain substances that others are not ..... but has anyone ever investigated the phenomenon of what wavelengths humans can see? Is it a person-to-person variable, or is it constant for everyone? Can some people see IR, red and green, for instance, instead of red, green and blue? Or green, blue and UV, for that matter ..... and what would it look like?
Je fume. Tu fumes. Nous fûmes!
That isn't sunny south Florida up there you know. At -40 degrees F (or C), the fewer electronics you have to keep going, the better. I don't know if that is part of the reason at all, but these are not simple commercial off-the-shelf cameras.
Hey,
:)
I totally agree with the lens being the most important thing.. I got annoyed at what i believe to be B.S. regarding his 'superior' (non existant) sensor.
It also wouldn't have been so aggravating if he hadn't gone to such extremes as saying:
"I have a old 2 megapixel digital camera that will beat the Best 4-6 megapixel consumer camera you can buy today."
I just don't buy it...
Not to mention "Nasa is not about to send the really low grade crap that is available to the cunsumer to another planet. they sent the real deal."
Err... I wasn't aware that nasa had somehow one-upped the current leaders in photo-sensors like Canon, Nikon, and Kodak that spent billions of dollars on R&D.
But whatever... everyone believes what they want. If sensationalist b.s. is good enough for you, then ok! (by 'you' i mean the generic 'you', not necessarily you you)
-Tomaj
very simple. it works exactly like the rover's camera. it has a 4 filter color wheel + real glass optics. it will automatically grab the 3 color shots (+ 1 gamma shot) and combine them in the camera before sending to the PC.
foveon technology is a neat hack... but it still sucks compared to how high res digital cameras have taken photos for the past 7 years. in high light it produces super photos of even moving objects. machinevision cameras have been this way for a really long time.
This problem is not unique to the Mars rovers.
As a hobby and as income, I make borosilicate lampwork beads and sell them on ebay. This requires me to take digital pictures of my beads, which I do with a Nikon Coolpix 885.
Every once in a while I run into a color combination that simply cannot be photographed correctly. One bead set I have looks brown/butterscotch/caramel to the eye, but when photographed using that particular camera, some of the brown features in the bead come out electric red.
They've taken several pictures of the lander platform in true color in order to calibrate the camera.
Err... I wasn't aware that nasa had somehow one-upped the current leaders in photo-sensors like Canon, Nikon, and Kodak that spent billions of dollars on R&D.
which explains alot about your lack of knowlege.
there is no chance in hell that nasa will send a unstable prototype to another planet. please give yourself a reality check.
A B&W sensor + color wheel will kick the living arse of ANYTHONG you can go out and buy right now in a Compusa/breast buy/whatever.. and THAT is what I was comparing to. I have onte that is 3 years old and explained it in my previous post to your drivel.
I sugest you tell me the first consumer electronics store with a HIGH end digital SLR + $1000+ lens... oh wait... you cant.
maybe you whould actually READ the post before foaming at the mouth... it makes you look like a complete fool.
Do not look at laser with remaining good eye.
Last time I checked, Martians have black skin, not green.
Given that we're having so much trouble figuring out what the human eye would see (w.r.t. color), I probably shouldn't even bother to ask, but does anyone know how bright Martian daylight would appear to the naked eye? Insufficiently bright for sunglasses, for example? How (un)comfortable would it be looking at the sun?
I know the human eye is fairly adaptive in this regard, but I'm curious about the qualitative answer to this question. (Quantitative answers expressed in lumens or whatever won't quite do it for me.)
As I understand it, the explanation is simply that the public was given pictures using filters intended for scientific research. This alters the printed colors. At this point NASA should have given more pictures that produce colors closely matching what the human eye sees. With color chips and photoshop(tm), along with a picture taken on earth before the mission, even I could come up with a presentable picture.
My local Apple Store sells the digital Canon Rebel. $999 with lens, $899 without. Not a HIGH end camera, but certainly better that the fixed-lens "consumer" cameras you seem so worked up over.
I don't know the date of the first use, but Sergei Mikhailovich Prokudin-Gorskii photographed parts of Russia for the Tsar in 1909.
He used a three photo technique where the scene was recorded three times on a glass plate (in a row, not overlaid) with different filters. If you look carefully at the river, there is color distortions from the small waves.
When you take a look at what this old-tech can really do, it's quite astounding.
The Library of Congress has an exhibition of pre-WWI (that's World War I) *color* photos of Russia shot using the exact same process. Since this was a while before any practical color photo printing processes the photographer built a "magic lantern" for "optical color projections."
Props to Bolo Boffin for the link.
Posting as AC as I only got this from another discussion eons ago and can't claim credit. Someone registered a username for slashdot and shared it with everyone:
User: Slashdot2001
PW: Slashdot2001
I personally think this should be at the top of every NYT linked story.
Read this and this. These are from the NASA Rover site and they explain it all.
- - - - - - - - - - -
I am a programmer. I am paid to produce syntax not grammar. Deal with it.
This isn't what JPL said. They said they were using a full color, basic digital camera. Damn, where's that link?
I think this paper by the lead scientist for the pancam project should be interesting to you guys.
e s/ pdf/bell_2003.pdf
http://europa.la.asu.edu:8585/PGG/greeley/cours
The last few pages contain all the nerd art.
It is so much better than all those superficial newspaper articles.
Prokudin-Gorskii travelled Russia taking color photos about a hundred years ago, a time when there was no color films. He used to take 3 pictures, one after another, each one with a different filter. He then projected the three together to get a color picture. Similar to Spirit but in a very, very old fashion.
so, i threw this one together the other day, is it anywhere close do you guys reckon?
Spirit-pano-rgb-compose.jpg
Software Freedom Day!.
The Library of Congress has an interesting exhibit up devoted to an early 20th century Russian photographer who used this exact technique. The site includes a very detailed description of how this filter system works, along with dozens of color pictures from the photographer's travels. It's definately worth taking a look at, if not for the description, then for some very cool pictures.
of some turn of the century russian color photos using the same or a similar technique. I like that people thought of doing stuff like this back then. It is amazing to see in color what things looked like back then. I think there are some from early in the 20th Century in New York online somewhere as well.
Funny how the rover got stuck
n .mov
http://images.spaceref.com/news/2004/rover.armspi
It's a Quicktime ".mov" file format. If you are deficient and still using Windows can probably play it in WMV or Real Player too, Linux users use Xine or MPlayer, if not go get the Penguin Liberation Front codecs (PLF).
Someone mirrior this quick before it's slashdotted!
>> it makes you look like a complete fool.
Pardon me, Lumpy ass, but I think you're the one who looks like a complete fool making claims for some notional camera that you own that probably doesn't exist.
Can you provide the technically curious amongst us with some actual information on this wunder kamera ?
.. If the blue on the color chip isn't visible using the infrared filter then the blue in the sky might not be visible either.
---- "Excuse me. Where's the children's gun section?"
For some people, everything else except what they own is junk.
The point is it's a 1 Megapixel camera taking the three colors, which is the exact same as a 3 Megapixel "normal" camera. Inside a 3 MP chip on a normal camera there is a little mask for each pixel that has the three filters on it.
Why isn't anyone talking about this?
maybe the rover cameras don't have a way to prevent infrared rays from registering on the CCDs, outside of the filter wheel?
that would certainly explain why a "visible red" photo is impossible to get for a true RGB composite, as IR rays arent blocked by a red filter.
Hi, if you have 3D glasses you can see the Mars Rover Images in 3D at http://science.discovery.com/convergence/mars/mars .html
Jax
Now the world has gone to bed,
Darkness won't engulf my head,
I can see by infra-red,
How I hate the night.
Oh, say does that Star-Spangled Banner entwine / The myrtle of Venus with Bacchus's vine?
Here it is: http://dsc.discovery.com/news/features/mars/slides how/mars3dslide.html
Jax
cool!
Well, since they're only using one camera, and switching the filters, that means we can never know the true color of Martians.
Thanks to you all for doing the dirty work for me. :)
-Tomaj
Thank you. This is a really neat link.
May we never see th
This is way off, you've somehow killed the little red, white, and blue flag on the arm.
Hey! Glad to be of service Tomaj!
Seriously tho, I hate it when gimps like 'Lumpy' make uninformed and unsubtantiated claims and the slashdotter pack just suck it all up (and mod it up too) - ugh!
Aside from the special testing that needs to be done to equipment to ensure that it can survive the hazards of space travel, there are technical reasons why one would choose not to use a commercial style multi-megapixel camera.
For one, higher megapixel cameras tend to be less sensitive, due to limitations in current chip design.
Two, you must ensure that the image sensor has a known and definable response to all of the various wavelengths that are important to scientific analysis. That likely includes several infrared bands and ultraviolet--not typically covered very well by commercial digital cameras.
Jim
Pioneer 10 and 11, which both flew past Jupiter in the mid 70's, used only a red and blue-green filter IIRC. They used these two colors to approximate full-color images based on earth-bound images. I don't remember anybody fussing about it back then. A disclaimer of sorts was usually in the more technical articles, but many articles said nothing about it.
Table-ized A.I.
I think people are also forgetting that, on Mars, white light is probably not reaching the surface. The dust in Mars' atmosphere is probably tinting the sunlight a little bit red, which certainly doesn't make getting the "correct" color easy.
But a comparison of the Mars Pathfinder images against the MER images shows that the colors in the MER images are too red. In the MPF images the rocks aren't all the same color.
It's pretty obvious that NASA's been doing a lot of Photoshopping on these images. While some Photoshop'ing is necessary (to merge the 3 grayscale images and to eliminate the seams in the panoramic images), I think they're overdoing it this time. I can't find the link right now, but there's one image in particular where it's blatantly obvious that they've replaced the sky with a single, solid color (you can see jaggies along the horizon in the high-resolution version).
I'm not trying to be all conspiracy theorist or anything. I certainly don't think they're faking the landings, nor do I think the Martian sky is bright blue as some have suggested.
If you use an infrared filter like the L2 filter on Sprit's Pancam, you get data that represents only things which reflect or emit light in that particular region of the spectrum. Anything that emits light ONLY in the red will be absent from the data set. It is possible for something that appears as a fairly monochromatic red to be entirely invisible. How can you use Photoshop to put back something that is invisible? You cannot.
You can adjust an individual colour in the image using a reference image taken with the appropriate filters, and that colour will then appear correct. Other colours, however, will remain distorted.
Worse, you cannot possibly know the emission/reflectivity spectrum of things on Mars, so any image you produce that appears to show the sundial colour chips correctly may distort terribly the Mars components of the image. It is not really very interesting to see a colour corrected photo of the sundial, is it? We could have achieved that without sending the rover all the way to Mars.
Nope, using a relatively narrow-band-pass infrared filter like the L2 simply leaves out information about the red part of the spectrum, and extrapolation only goes so far in recreating that data. Non-linear data - discontinuities within the missing portion of the spectrum - are simply gone, never to be retrieved.
Also, NASA is lying. Perhaps 'lying' is too strong a word, but they are either deceiving us or they are operating under a serious misconception.
"We just made a mistake," said Dr. James F. Bell III, the lead scientist for the camera. "It's really just a mess-up." Well, NASA claims to be releasing the raw data from Spirit on its web site, but the raw data does not contain any image sets for the panoramas taken with the L4, L5, L6 filters. They have almost never used the L4 filter.
So either the "mess up" is that they have forgotten to use the L4 filter from day one (unlikely, since each photograph taken presents another opportunity to switch to the L4) or that they have L4 images but they are not releasing them, in which case they really are not releasing the raw data.
The argument about the L2 being better for science is bogus. There's no way that NASA scientists are doing serious mineral analysis with a pretty, stitched-together wide view panorama. That's just rubbish. they would be looking at detail images, and possibly comparing between detail-level images. The panoramas are strictly for public consumption, and maybe office posters at JPL.
It's probably not a conspiracy, but it is a mystery.
...on an Amiga!
I have it on pretty good authority that it is part of the airbag.
Just wait for more images from MER-B (Opportunity). You're about to see some really cool stuff in the next few days. No Martian crabs or bunnies, I'm afraid, but still some awesome stuff.
isnt this why they put a sundial on the blasted thing? or was that one of the other things we recently crashed into mars.
- Info (src: Athena)
- Tech Briefing (PDF 52 KB)
- Info (src: Planetary Society)
- Info (src: NASA)
- Info (src: Caves of Mars).
- Filter Specs
(showing approximate color swatches in browser).
--For news, status, updates, scientific info, images, video, and more, check out:
(AXCH) 2004 Mars Exploration Rovers - News, Status, Technical Info, History.
Take a look: More info and pictures of Fulgurites on Earth .
;-)
They look exactly like that thing on Mars.
BTW, Fulgurite reminds me of the Wizard's bad-ass "F" spell in Ultima 3 (Fulgar).
--
For news, status, updates, scientific info, images, video, and more, check out:
(AXCH) 2004 Mars Exploration Rovers - News, Status, Technical Info, History.
Very good, technical article making point that NASA is not altering colors on Mars (beyond normal minimal adjustments to generate color images, of course).
--
For news, status, updates, scientific info, images, video, and more, check out:
(AXCH) 2004 Mars Exploration Rovers - News, Status, Technical Info, History.
Nice of them to give a good explanation :). All they need to do now is note that on the pics on their site.
GPLv2: I want my rights, I want my phone call! DRM: What use is a phone call, if you are unable to speak?
I'm sorry but the 3D images really suck!
Hasn't everyone learned that since they came out in the 70s?
Thanks for opining. These happen to be from NASA and are really high quality. The 3 dimensional aspect is sharp even to "the most casual observer (wearing 3D glasses)."
Jax
So it's useless in a dynamic environment. I think I'll stick with my cheap 4 megapixel consumer grade camera, thanks.
Are you always this negative(????)...you might want to look inside of yourself for your Zen.
Jax
Ok, I read the story, and read the comments.
NASA says they goofed and the pancam pix don't reflect what the human eye would see. (But that they could make those pix if they wanted to.)
What I don't see are links to the correct pictures. Not in the NYT story, not in the slashdot blurb, and not in the comments.
What gives?
Not quite correct. The raw image has high definition luminance information, but the chrominance information requires clusters of three pixels. It really depends upon the image processing algorithms in the camera as to how this is used.
Hm. I'm no meteorologist, but I wasn't seeing any evidence of a dusty atmosphere in any of those rover images. --Details at distance seemed as clear as near objects. There's WAY more crap in Earth's much more robust atmosphere, and we get plenty of white light.
-FL
The Viking probes used a very basic tool to send back accurate color information.
"The correct way to do it, and the way it was done 30 years ago with the Viking spacecraft, is to have a COLOR CHART attached to the side of the rover. For Viking it was attached to the side of the housing for the electronics. The camera which is remote controlled, is aimed at the chart. The colors are then adjusted as required so the color chart looks the SAME as it did on earth. That's all there is to it."
Easy and low-tech, and there's only two possible excuses for this solution not being used with the current probes. .
1. Total incompetence, (which frankly, is entirely possible these days given NASA's slipshod workings.)
2. The convenience of being able to cover up inconvenient images with bullshit excuses.
-FL
Now I know why blue films look blue :)
yes, that's a good point, have you got any better idea which image on the gallery corresponds to which filter colour?
Software Freedom Day!.
As I said, the public should have been given new pictures. Even though you may not have the full third color, with a little extrapolation, a "third" image could have been made to approximate the third color, (in this case; red) and the three combined to give a nearly correct view of the landscape. Along with it, NASA should have explained that the colors were as close as they could come to the correct color and that when the filters could be made to work properly the expected pictures would be forthcoming. I would further imagine that in an attempt to put out early publicity pictures, the first available raw data was used. Even the project I designed for the space station will have very slow data transmission since it has to compete with all the other streams of data used for various sensors. High resolution images from Mars will arrive painfully slow.
In addition, I would not be surprised to find that some of the mechanics are not working properly in the cold temperatures.
ok, i think they must've added the 6th image in that series later on, because there are certainly more in there than before, i think i'll have a go with the sundial next.
anyway, this one Spirit-pano-rgb-compose2.jpg uses the previously unavailable L6 and gets the US flag just about right.
Software Freedom Day!.
Anyway, the color of the sky, (on a clear day at any rate), is probably determined by the gas content of the atmosphere rather than particulate matter. I wonder what the Martian atmosphere is made out of. . . (Could look it up, but I'm feeling lazy.)
Though, yeah, you're definitely right. I remember now that the surface of Mars would get fuzzy from time to time depending on how much sand-storm activity is going on. There's obviously enough air/wind to move dust around!
-FL
Actually, they now have a lot of RAW pics taken with L4,L5a and L6 filters. :)
If you combine them yourself you get very different results to the NASA ones. Instead of washed out sepia toned pics you get a much clearer result.
You can also see that both rovers landed in very different terrain.
Combine the pics yourself and see. Spirit's environment has all that nice red/ochre sand that we all know and love, but Opportunity is rolling about over bluey/black material with the red colour poking through from time to time. In fact, if you look at the closer images of the rock outcrops, you can see blue, spherical pebbles being eroded out of the rocks!
Whatever the controversies about the colouring of the pics, you can't help but be totally awed by the whole thing, and at least NASA is nice enough to make the RAW pictures available for us to play with ourselves
RebateFX.com - Spread rebates for Forex traders
The same story already appeared on /. three weeks ago, before the NYTimes picked it up, and with more technical details.
As mentioned here (pdf, google-converted, orriginal pdf here) the rovers use The ICER Progressive Wavelet Image Compressor, which according to JPL (googlified de-pdfing again, original here) ;)
Both lossless and lossy compression will be used, depending on how critical or scientific the data is.
The 2nd pdf goes into depth about how the algorthims are used and is probably an interesting read for someone who has a greater understanding of maths and compression techniques
Music is everybody's possession.
It's only publishers who think that people own it.
Fuck Beta
~John Lenno
For those who wish to combine the RGB channels themselves, here is the breakdown for Spirit:
Sol007 - one image set, Sol008 - one image set (1 horizon), Sol009 - twelve image sets (5 horizon), Sol011 - five image sets, Sol012 - four image sets, Sol026 - two image sets, Sol030 - two image sets
I'm pretty sure the data from even the best day, Sol009, is insufficient to combine into a "true colour" panorama (like the one they released on 12-Jan-2004), with only 5 horizon shots. The aberrant colours in that image and the others around that time gave rise to this whole controversy, so it is significant that we don't have enough L4,L5,L6 sets to create a nice big picture.
Interestingly, they have added more images to Sols 9, 11 and 12 since my first and second analyses of the raw data. I believe that they are now posting web pages with blank spaces to indicate missing data, which would be very helpful to those of us who wish to know when all the data has been posted.
Anyway, it is pretty obvious that Spirit is capable of doing L4,L5,L6 sets, and also that there were some holes in the raw data as originally posted at JPL. I suppose this whole issue was a failure of NASA to understand the need for RGB channel images for P.R. purposes. They have probably never had their data examined carefully by so many people.
Now I'm off to look at Opportunity again!
Doesn't happen very often, but today it did. Good call. Be careful, though, not to make the mistake of thinking that my being clued-out this time makes me wrong every time, or even most of the time. The name of the game is thinking out loud and fact checking. I raise points as I see them, and think throught them as I am able, and I am just as happy to be called on a bad point as I am to contribute a good one. This is about learning for everybody, and Slashdot is actually a pretty good crucible.
Thanks for playing. Makes us all stronger.
-FL
So then the color images taken on Mars are probably shifted a bit to a butterscotch shading were human eyes there to see the actual environment.
Fair enough. --In any case, I was under the false impression that the current crop of landers didn't have color correction charts mounted for their cameras to check against. Must remember to double-check my sources.
-FL
FL - are you familiar with this site - Goro Adachi has been following the mars landers and their pictures, and been pointing out how the colors of the mars pictures are fixed before they get released to the public.
I think you will find it interesting - he uses pictures of the rovers here to compare colors as they appear in the pics from mars.....
Such a gracious concession is quite a rarity around here! Apologies for my rather confrontational style - I do like hard (though fair) discussions, and poking fun at your post by mirroring it was just too hard to resist... thanks for taking it so well, looking forward to our next bout! :-)
Be faithful to your obsessions. Identify them and be faithful to them, let them guide you like a sleepwalker. JG Ballard
It's funny what a person can get used to.
It just occurred to me that your comment is amazing. I mean, that a random computer user -- probably not associated with NASA or any sort of scientific research organization -- can casually say that she just reviewed the raw data from a machine on another planet...that's just astounding, isn't it?
...Sorry, the No-Doz must be kicking in.