HN

Need help?
<- Back
NASA Color Trick Was Meant for Mars. Now It's Unveiling Rock Art on Earth

NASA Color Trick Was Meant for Mars. Now It's Unveiling Rock Art on Earth

gumby

Comments (30)

  • pimlottc
    This is based off a NASA article, which has an expanded version with more details here:https://spinoff.nasa.gov/Manipulating_Satellite_Photos_Now_R...
  • Waterluvian
    False colour composites were something I was introduced to in high school GIS and did a lot of in undergrad remote sensing. It was one of those Eureka! moments for me in terms of developing a better understanding of signals and signal processing, as well as sensors and data collection. Ie. absorbing the reality that the way in which my eyes (or any optical sensor) see the world is not canonical. Vegetation is red, not green!It was also just the COOLEST THING EVER to swap infrared bands in LANDSAT ETM+ imagery and watch vegetation immediately pop out at you. It's what turned this sort of dull (at least for a teenager) geoscience into a kind of puzzle where you have to figure out how to bring the signal up out of the data.
  • matja
    You can do something similar in GIMP:1) Colors > Components > Decompose > LAB2) For the layers of the A/B (chroma) channels, Colors > Levels > "Auto Input Levels" (maximize the contrast), and move the mid point to the median.3) Colors > Components > Compose > LAB
  • qurren
    I tried to look for hidden rock art at Ankgor Wat by imaging with multiple bandpass filters and amplifying cross-spectral differences. I didn't succeed, but maybe I was in the wrong place. The shit guards there also didn't like me using a tripod while I changed filters, so it was also hasty.
  • mlmonkey
    Is there an imagemagick implementation that I can just throw into the pipeline?
  • 1shooner
    DStretch is also really great at revealing painted ghost signs on old buildings.
  • dylan604
    “No one really knows why people made the rock art they made, at least in many cases,” Harman saidWell, it's obvious they really wanted to though. This isn't like marking on a wall with a Sharpie. They had to work at it to make it happen. The commitment alone is impressive even if it was just a "Grogg was here!"
  • HPsquared
    See also: Eulerian Video Magnification (EVM) to amplify subtle motions and colour changes:https://youtu.be/ONZcjs1Pjmk https://youtu.be/_qtzWNZApsw
  • NDlurker
    Amazing. This will change how I take photos
  • cwmoore
    No tricycle-riding penguins yet.In reality very interesting work and results, but a little disturbing that it took three or four decades and a self-funded citizen scientist to transfer the knowledge to the application.
  • tedecristal
    any repo or link where other people can try?
  • xd1936
    "Why do we need to spend resources trying to go to space, when there are problems right here on Earth that need solving?"