Yet another Hacker News

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

119 points gumby 3 hours ago 21 comments

NDlurker 2 hours ago | parent

Amazing. This will change how I take photos

Aboutplants 1 hour ago | parent

Going to be taking a lot more pictures of rock faces!

NDlurker 46 minutes ago | parent

I want to try this on faded graffiti. I have a few spots in mind already.

tedecristal 2 hours ago | parent

any repo or link where other people can try?

ortusdux 2 hours ago | parent

Matlab - https://www.mathworks.com/help/images/enhance-color-separati...

This paper might also be of interest - https://www.mdpi.com/2227-7390/13/20/3297

"In this paper, we review the theory behind decorrelation stretch and propose some alternative algorithms that resolve the issues of the standard approach."

pimlottc 2 hours ago | parent

The app is called DStretch, it's available for iOS and Android

https://dstretch.com/Apps/index.html

Aboutplants 2 minutes ago | parent

Someone needs to vibecode some updated options

ButlerianJihad 1 hour ago | parent

"A contribution is mandatory before I will send the plugin. It may take me a few days to respond, have patience. Please note that the plugin is not an app. It has much more functionality than is possible in an app on a smartphone."

"The DStretch [mobile] app is a lightweight version of DStretch intended to give users the ability to enhance rock art in the field. It is not a substitute for the DStretch plugin which has much more functionality."

pimlottc 2 hours ago | parent

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...

homeonthemtn 1 hour ago | parent

Way better, thank you

cwmoore 2 hours ago | parent

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.

HPsquared 2 hours ago | parent

See also: Eulerian Video Magnification (EVM) to amplify subtle motions and colour changes:

https://youtu.be/ONZcjs1Pjmk https://youtu.be/_qtzWNZApsw

dylan604 2 hours ago | parent

“No one really knows why people made the rock art they made, at least in many cases,” Harman said

Well, 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!"

Terr_ 22 minutes ago | parent

https://smbc-comics.com/comic/rite-on

> "No matter what you do, when we find something weird in ancient history we will decide it must've been part of a fertility rite."

matja 1 hour ago | parent

You can do something similar in GIMP:

1) Colors > Components > Decompose > LAB

2) 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

MisterTea 12 minutes ago | parent

Can you explain 2 a bit more? I see the Auto input levels but unsure what you mean by "move the midpoint to the median."

The result I got for the original mars image was a washed out red image with some yellow around the craters.

mlmonkey 1 hour ago | parent

Is there an imagemagick implementation that I can just throw into the pipeline?

xd1936 46 minutes ago | parent

"Why do we need to spend resources trying to go to space, when there are problems right here on Earth that need solving?"

timschmidt 42 minutes ago | parent

Weather satellites have done more to increase crop yield than anything since the invention of artificial fertilizer and save more lives.

qurren 11 minutes ago | parent

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.