[HN Gopher] First TV Image of Mars: Interplanetary color by numb...
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First TV Image of Mars: Interplanetary color by numbers (2016)
Author : gdubs
Score : 144 points
Date : 2022-12-31 17:45 UTC (5 hours ago)
(HTM) web link (www.directedplay.com)
(TXT) w3m dump (www.directedplay.com)
| ryantgtg wrote:
| Kottke is back!
| [deleted]
| guidoism wrote:
| When my dad was working on Landsat images in the early 1970s they
| used to print out pages upon pages of numbers, color them in with
| markers, tape them up on a big wall, and then take a picture of
| it with a regular color camera. _That_ is how they could print
| out color satellite images!
| davchana wrote:
| I did something in reverse. Our project was to maintain about
| 200 miles of a straight road in a diagonal direction on north-
| uo map, with another 90 miles road cutting it through making it
| a lop sided X.
|
| I screenshotted Google Maps satellite view at certain height.
| It were about 30 sgots wide & 50 shots tall. Then cropped out
| the rectangle from shot with no distance scale, or search box.
| Then joined everything in Photoshop by hand. Then printed it as
| one gigantic page pdf. Then printed it on A3 pages as tiles
| with 1 inch overlap. Portrait wise 5 pages wide & 4 tall. Then
| trimmed every sheet on right & bottom except the last sheet on
| left & bottom. Then pasted them with glue. Cello tape on the
| back. Then everything goes on the wall. Then other people could
| use pushpins & stuff to mark the progress & program.
| lisper wrote:
| People forget that cut-and-paste used to be _literally_ cut
| and paste.
| RheingoldRiver wrote:
| Incredibly trivial example but, I did this for baseball
| score cards as a kid. My dad had internet at work but we
| didn't at home, so he printed some baseball score cards for
| me at work, and brought them home so I could pick one. But
| I wasn't happy with any particular one of them, so I went
| to our local copy shop and sat there for a couple hours
| happily cutting and gluing together the elements from all
| of them that I wanted to create the ultimate baseball score
| card.
| VincentEvans wrote:
| [flagged]
| lanewinfield wrote:
| For those in or are visiting the LA area, this image is on
| display on the free-to-the-public JPL tour. Highly recommend!
|
| https://jpl.nasa.gov/events/tours/
| pvorb wrote:
| > Though he used a brown/red color scheme, the thought that Mars
| was red did not enter his mind. [...] It is uncanny how close his
| color scheme is to the actual colors of Mars. It's as if they
| came right out of current images of the planet.
|
| I'm sceptical. If you look at Mars from Earth, you can see it's
| red even without a telescope.
| abhorrence wrote:
| The article isn't saying that he didn't know it was red, but
| rather that he wasn't actively thinking about trying to match
| the color. Obviously there's a question of conscious vs
| subconscious thought, but the claim is at least that he chose
| red/brown because it would represent grayscale well.
| m463 wrote:
| Coming from a blue planet there might be some color bias. We
| should really observe from the moon which seems to have a
| neutral color.
| wheelerof4te wrote:
| Yeah, I'm pretty sure that the science guy in the 70's knew
| which color Mars was.
| [deleted]
| jeffbee wrote:
| It does not make a lot of sense to me that it would take hours
| for a computer to generate an image, but the computer could
| promptly print out the data in human decimal representation.
| idlewords wrote:
| The issue was not processing time but bitrate. Mariner 4 sent
| data back at something like 8 bits per second, and the science
| team printed it and colored it as it came in.
| JoeAltmaier wrote:
| I agree. I used to print images by using characters with more
| ink for the darker blots, down to a single dot (period) or even
| a blank space for the lightest. Looked pretty good.
| lisper wrote:
| You have to remember that back in those days, for a computer to
| generate an image did not mean for it to render an image on a
| screen like we do today. It meant generating an image to be
| _printed on paper_ using the same kind of technology that was
| used for printing magazines and newspapers. That was a time-
| consuming _physical_ process, not so much a time-consuming
| computational process (though it was probably that too back in
| 1965).
| osigurdson wrote:
| >> "The thought that Mars was red did not enter his mind".
|
| Not sure about that. It was assumed to be red since 400BC [1].
| One needs only to look at it without the aid of a telescope to
| jump to the conclusion that it might be red.
|
| [1] https://mars.nasa.gov/allaboutmars/mystique/history/early/
| [deleted]
| ncallaway wrote:
| To me that sentence doesn't mean "the scientist didn't know
| Mars was probably red", but rather means "the scientist didn't
| pick red to try and color match Mars, but for a different
| reason"
| osigurdson wrote:
| It seems unlikely to me. I get that he wanted to do greyscale
| since that is all of the information that the sensors
| provided. However, picking a non-red colour set, knowing that
| the planet is red is absurd.
| sidpatil wrote:
| This technique is generally known as _indexed color_.
|
| https://en.wikipedia.org/wiki/Indexed_color
| nneonneo wrote:
| It's simpler than that; the pixels were just light intensity
| values (per the article, they had originally intended to get
| various shades of grey chalk). The scientists just wound up
| applying their own "palette" to the intensity values.
| f272529 wrote:
| [flagged]
| 082349872349872 wrote:
| Does "Paint-by-Numbers" no longer mean indexed colour to the
| general population?
|
| https://en.wikipedia.org/wiki/Paint_by_number#/media/File:Ka.
| ..
| munchbunny wrote:
| It usually does, but the article talks about manually
| drawing out a grayscale image by following luminance
| numbers. That's generally not considered "indexed color"
| unless you're using a mapping of pixel values to grayscale
| values (indexing) to reduce the number of valid pixel
| values for compression purposes.
| rzzzt wrote:
| This technique is generally known as _false color_.
|
| https://en.wikipedia.org/wiki/False_color
| Sniffnoy wrote:
| I mean, I would associate the term pretty strongly with
| indexed color with irregular regions, not with square
| pixels.
| grogenaut wrote:
| To me it means I as a bad artist am just filling in colors
| likely with really bad color mixes on an image. It has a
| connotation of really low end art.
| [deleted]
| dang wrote:
| Url changed from https://kottke.org/22/12/our-first-closeup-
| image-of-mars-was..., which points to this.
| tmpburning wrote:
| That's kind of a weird way to put it... as if the image came from
| the TV?
| Dylan16807 wrote:
| Is there anywhere to get the actual image data, in either text or
| bitmap form? The photo of the print version isn't terrible but
| it's not particularly good either.
| poszlem wrote:
| Makes me think of the early satellite photography that was
| captured using analogue cameras, which were mounted on satellites
| orbiting the Earth. When the satellite finished its mission, the
| camera would be released and fall back to Earth, attached to a
| parachute. A team of technicians would then locate the camera,
| retrieve it, and bring it back to a laboratory where the film
| would be developed by hand in a dark room. This process was
| labor-intensive and required a great deal of expertise in order
| to produce high-quality images.
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(page generated 2022-12-31 23:00 UTC)