Hacker News Reader

Comment by thaumaturgy | Hacker News Reader

Not directly apropos, but the current best answer on that page is probably good enough to have been worth money to NASA, and somebody just did it for free because it was a neat problem to solve and they could.

This is probably my favorite thing about the internet.

View on HN

It's a very good answer, and it worked very well in this case, but it's nothing revolutionary. Background modelling with a single Gaussian is a pretty standard computer vision technique, and he's essentially finding anomalies by backprojecting the model[1]. This is great for one image when you can grab a sand patch, but you'll need to recalculate the model if/when the lighting changes.

If you're interested, more advanced techniques will look at Gaussian Mixture Models, which essentially can model the background (i.e. the sand) as the sum of several Gaussians (thereby permitting multiple distributions, e.g. sand in light vs. sand in shade); for example, GrabCut[2] uses GMMs to model foreground and background distributions for background segmentation. This still won't work for changing lighting, for that you need something more advanced which changes the model over time.

[1] E.g. backprojecting a histogram in opencv: http://docs.opencv.org/modules/imgproc/doc/histograms.html#c...

[2] http://research.microsoft.com/en-us/um/cambridge/projects/vi...

EDIT: I realised that I sound very negative in this reply, which was not my intention. The technique used is great for the problem they were trying to solve, and I'm glad to see people sharing these sorts of answers on the internet for free.

Somewhere his boss is wondering what on earth that guy was doing all day.

Yet, he has demonstrated to a wide audience what good image processing and lateral thinking can do, he has brushed up on a few parts of mathematica he has not used this past quarter and the world is a little bit richer

A TED talk recently mentioned how robots are replacing us and we need to manage a jobless future - this indicates how we might do it.

Plus, I cannot work out which is worse - that bits of metal are dropping off the Rover. Or not ...

Do you mind providing a link to the TED talk in question? Been thinking about that kind of future lately, and was wondering what other people (who've probably thought about it for longer) have to say about such future.

I second that. I would like to see what that TED talk has to say about keeping humans employed in something for as long as possible.

I want to think software engineering/programming would be one of the last jobs to be replaced by machines. It would last until the "singularity" is reached which is when computers would be able to program themselves (re-writing and improving their own code exponentially).

One idea I came across a while ago is the idea of a 'national dividend'. Basically everyone gets a base amount of money you could live off. If people want to work harder and earn more money, they are free to. Unfortunately I can't recall the book I read it in.

Maybe 'The Lights in the Tunnel: Automation, Accelerating Technology and the Economy of the Future' by Martin Ford?

I haven't finished the whole thing yet, but so far it has been a good read about some of the problems with increased automation and machine intelligence. He also outlines some possible solutions.

http://www.amazon.com/The-Lights-Tunnel-Automation-Accelerat...

I have seen it from Charles Handy and others as well. It is all about the idea that currently the vast wealth of society is generated unevenly, so some form of redistribution is needed - a job for everyone is the current approach. But when those jobs get replaced how do we redistribute?

It's going to be a rough century

I've heard this view before. It's what I have been saying for some time now: With vastly increased wealth for the richest due to technological leverage, what will need to be done is increased taxation, especially for the richest. The taxes can be used to pay for a "dividend" system, which could for instance be implemented through negative taxation up to a certain low income. We might not be there today, but it is where we'll end up if automation keeps spreading at the rate it has until now.

Norway almost de facto has a system like this already (through an incredibly generous welfare system), but the only reason we are able to pay for it is through the huge petroleum income.

I think this [1] is the one lifeisstillgood meant.

[1] http://www.ted.com/talks/andrew_mcafee_are_droids_taking_our...

Yes, iespecially like the graph of human prosperity plotted against rises of religions, empires, plagues etc.

I would check his methodology carefully (he glosses over a lot) but the overall thrust is compelling

I agree, that is an awesome answer. Really brings home how much more powerful tools are today than they were when this sort of analysis took 'big iron' (like a PDP-10 with a Vector Coprocessor)

I'm pretty sure that NASA scientists are able to do this kind of anomaly detection and that the primary goal of this (interesting!) question is only trivia.

Of course they are, but NASA still pays them to do it.

Yeah, this is my favorite thing about stack exchange too.

true, this is great work done by the community...in other words the developer community specially at Stack.... website is really smart and good!

Reply on news.ycombinator.com