Russian Satellite Takes Most Detailed 121-Megapixel Image of Earth Yet
Diggester writes "The satellite, known as Elektro-L No.1, took an image from its stationary point over 35,000 kilometers above the Indian Ocean. This is the most detailed image of the Earth yet available, capturing the Earth in a single shot with 121-megapixels. NASA satellites use a collection of pictures from multiple flybys stitched together. The detail in the pic is just amazing."
Also, I looked at the zoomable image and zoomed in all the way in and.... saw mostly macroblocks? Is that still "amazing detail" in a sense that eludes me?
One reason the NASA global-coverage image sets that were released in 2002 (with updates starting in 2005) have become the de-facto standard source is that: 1) anyone can download them; and 2) they're in the public domain, so anyone can use them for any purpose. You can get a bunch of versions here and from the Visible Earth site linked at the bottom of that page.
This one looks cool, but further use will be limited if the only thing I can do with it is look at it in this online zooming browser.
10 PRINT CHR$(205.5+RND(1)); : GOTO 10
It looks photoshopped because it includes false color data from an infrared cam. It's not photoshopped.
I specified that based on visual acuity limits. There's a lot of optical theory explaining why over 300 dpi is mostly useless for toner on paper. Unless your eyeball lens diameter is 10 times bigger than the average human or your retina cell layout is different than all known humans, it is not optically possible to resolve 3000 dpi or whatever on paper under normal conditions and lighting. Depending on how close you can hold the paper before you can't focus on it anymore, and tangentially depending on how bright the light it (little pinhole camera iris) humans top out around 300 dpi.
Now, projected thru transparencies onto a overhead, higher res works, if you have old fashioned overhead projectors and sit close to the screen. Also there are ugly aliasing and anti-aliasing effects that can be avoided by higher res with real vector scaling. And high res allows better/smoother color mixing, in that bluring together 2**8 pixels of 2**16 color is the same as one 2**24 pixel, more or less. There are also relative brightness/consistency effects where making a "line" that varies from 8 to 9 pixels wide looks a lot less consistent than a line that is 85 or 86 pixels wide at 10 times the res, look at the percentage variation of one pixel. If the lighting is really bad, there are strange shadow effects where you can perceive over 300 dpi if the shadows land just right. Also there are some strange toner based textural issues where the plastic surface of thinner lines literally looks different. And some 3-d effects of toner on paper. So over 300 dpi is not a complete waste of time, just mostly a waste with average pictures under average conditions. It would be extremely hard to justify over 1200 dpi even in the weirdest corner cases.
"Science flies us to the moon. Religion flies us into buildings." - Victor Stenger