> To put that in perspective, 700 trillion pixels is 70 times more than there are estimated galaxies in the universe according to Google, or just seven Zimbabwean 100 trillion dollar notes.
...
How about this instead: a 700-trillion pixel world map, if displayed at the 401ppi of the iPhone 6 plus, would be 2.8km^2 and cover 4/5 of Central Park.
Yeah, it was a bit. I took it to be emphasising how although it's a huge number by natural standards, humans do some silly things with numbers at times so we get desensitised to their scale.
I think the most interesting part of this news is that they took an image processing technique and applied it on this large of a scale. They're doing background extraction on the entire set of satellite data.
I would be extremely surprised if they were actually doing that, because a lot of effort has already been put into doing it a better (and more interesting) way: cloud detection and mosaicing. Landsat captures several spectral bands, and due to atmospheric transmission rates, some bands can act as really good cloud filters [0].
This is what they're actually using, or something very close to it, for clouds [1].
10 comments
[ 4.0 ms ] story [ 36.4 ms ] threadhttps://www.google.com/maps/@-10.4886918,105.6396568,20430m/...
...
How about this instead: a 700-trillion pixel world map, if displayed at the 401ppi of the iPhone 6 plus, would be 2.8km^2 and cover 4/5 of Central Park.
An example can be found here: http://opencvpython.blogspot.com/2012/07/background-extracti...
This is what they're actually using, or something very close to it, for clouds [1].
[0] http://landsat.usgs.gov/ldcm_vs_previous.php
[1] https://github.com/USGS-EROS/espa-cloud-masking