ComputerVisionWiki.org
computervisionwiki.org
ComputerVisionWiki.org
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Re: ComputerVisionWiki.org
#2Could any one suggest a good book on Vision. Something like Cormen for algorithms.
Re: ComputerVisionWiki.org
#3Could any one suggest a good book on Vision. Something like Cormen for algorithms.
Here are some background and pointers. I'm not a computer vision guy, but these might get you started.
Computer vision is really hard. The computational resources we can spend on the problem are orders of magnitude smaller than what we're trying to emulate in the nature. I think (IANACVS!) something like 35% of the human brain's processing capacity deals with vision, for example. So the discipline is both highly mathematical (to root out shortcuts and shrink the problem) and computationally intense. Also, it's often got some kind of real-time requirements.
Don't let me discourage you though. Since I don't know much about the field, I don't know any of its successes. CV researchers have produced useful systems.
1. Image transform methods: looking up the 2D Fourier transform might be a good start.
2. Variational methods. These are hard to explain as they relate to vision, but if you read the first few chapters of Sussman & Wisdom's Structure & Interpretation of Classical Mechanics, you'll get an idea of what they're talking about.
3. Anything that involves sensors also involves noise. At my school, the first stage of the graduate CV track is a course based on [Papoulis & Pillai]'s Probability, Random Variables, and Stochastic Processes.
4. One of my classmates was involved in object modeling with manifolds. A manifold is basically an n-dimensional shape that follows mostly-Euclidean rules like a sphere, torus, or pretzel. I have no idea what to recommend here, because my curiosity about manifolds and repeated frustration in my efforts to find out more about them ultimately landed me in grad school. Watch out for that.
5. Obviously I know more about software than hardware, but you could definitely do worse than reading up on commonly-used sensors. A midlevel text on CCD cameras would be the way to go here.
6. You can read up on Visual Perception in humans. When I took a class on this as an undergrad, it was a senior-level psych elective. A related field is Psychophysics, which uses methods from physics to study sensory stimuli (e.g. acoustic waves) as they relate to perceived experience. See #s 1 and 3 above.
Hope some of this helps.
Re: ComputerVisionWiki.org
#4Could any one suggest a good book on Vision. Something like Cormen for algorithms.
The reason there isn't a definitive text on vision is that vision doesn't work. Algorithms work, and so to have a definitive text, you just collect up all the notable ones that work, and write about them in a book. When you have a totally unsolved problem like vision (outside of certain highly constrained domains, like robot soccer, where the colors are guaranteed, or industrial tasks, where basically the whole scene is guaranteed), you basically have to choose which methods that currently don't work might have a chance of eventually leading to something that does work. There are many possible sets of choices for that, which is why you can't really have a definitive text.
Re: ComputerVisionWiki.org
#5Could any one suggest a good book on Vision. Something like Cormen for algorithms.
The reason there isn't a definitive text on vision is that vision doesn't work. Algorithms work, and so to have a definitive text, you just collect up all the notable ones that work, and write about them in a book. When you have a totally unsolved problem like vision (outside of certain highly constrained domains, like robot soccer, where the colors are guaranteed, or industrial tasks, where basically the whole scene…
What do you mean 'work'? There are many highly nontrivial successes in computer vision. Take a look at some of the examples here: http://yann.lecun.com/exdb/lenet/index.html
They're pretty surprisingly effective. Or how about melanoma detection and discrimination from benign lesions here: http://scholarsmine.umr.edu/post_prints/00312091_09007dcc803...
Or with this thing? http://www.polartechnics.com.au/IRM/Content/products_solar_o...
Mathematics was hardly cut and dry before Bertrand Russell wrote Principia Mathematica, but that book still have tremendous value (if only as a beacon!) There was plenty more to discover in geometry when Euclid wrote the elements.
A good computer vision book, even one that simply cataloged important successes and failures, would be quite valuable. It's not that it hasn't been written because it can't be, it's that it hasn't been written because no one has really gotten around to it. Good textbooks require a massive amount of effort to get right.
Re: ComputerVisionWiki.org
#6Earlier quoted context omitted.
The reason there isn't a definitive text on vision is that vision doesn't work. Algorithms work, and so to have a definitive text, you just collect up all the notable ones that work, and write about them in a book. When you have a totally unsolved problem like vision (outside of certain highly constrained domains, like robot soccer, where the colors are guaranteed, or industrial tasks, where basically the whole scene…
What do you mean 'work'? There are many highly nontrivial successes in computer vision. Take a look at some of the examples here: http://yann.lecun.com/exdb/lenet/index.html They're pretty surprisingly effective. Or how about melanoma detection and discrimination from benign lesions here: http://scholarsmine.umr.edu/post_prints/00312091_09007dcc803... Or with this thing? http://www.polartechnics.com.au/IRM/Content/pr…
It doesn't work in the sense everybody most wants it to work, which is to slap a cheap CCD camera or three on top of a mobile robot and have it tell the robot everything about its surroundings, like human vision can. Yeah, if you point a camera at a very restricted specific set of objects, all lit the same way, and all in generally the same basic configuration, you can do some vaguely useful statistics to get some information out of it, but that's kind of a painfully limiting thing.
Put it this way: At Anybots, we have a robot with 16 cameras on its head. We pump all those cameras back to an operator station, stitch them all together in a vaguely fitting-together way, and then project them onto a big bank of monitors. Plop a human operator in front of the monitors, and he knows exactly the orientation of the robot, the configuration of its limbs, and has basically a 3d map of the entire scene and a model of the lighting, minus occlusions. I'm pretty sure nobody knows how to write a computer vision system to do that. I'm not even sure that anybody knows how to use the overlap in the cameras to figure out how to make a coherent nice projection of the cameras onto the monitors.
Re: ComputerVisionWiki.org
#7Earlier quoted context omitted.
What do you mean 'work'? There are many highly nontrivial successes in computer vision. Take a look at some of the examples here: http://yann.lecun.com/exdb/lenet/index.html They're pretty surprisingly effective. Or how about melanoma detection and discrimination from benign lesions here: http://scholarsmine.umr.edu/post_prints/00312091_09007dcc803... Or with this thing? http://www.polartechnics.com.au/IRM/Content/pr…
It doesn't work in the sense everybody most wants it to work, which is to slap a cheap CCD camera or three on top of a mobile robot and have it tell the robot everything about its surroundings, like human vision can. Yeah, if you point a camera at a very restricted specific set of objects, all lit the same way, and all in generally the same basic configuration, you can do some vaguely useful statistics to get some in…
Sure, it doesn't work like magic. There's still a decent case for a book...
Re: ComputerVisionWiki.org
#8Earlier quoted context omitted.
What do you mean 'work'? There are many highly nontrivial successes in computer vision. Take a look at some of the examples here: http://yann.lecun.com/exdb/lenet/index.html They're pretty surprisingly effective. Or how about melanoma detection and discrimination from benign lesions here: http://scholarsmine.umr.edu/post_prints/00312091_09007dcc803... Or with this thing? http://www.polartechnics.com.au/IRM/Content/pr…
It doesn't work in the sense everybody most wants it to work, which is to slap a cheap CCD camera or three on top of a mobile robot and have it tell the robot everything about its surroundings, like human vision can. Yeah, if you point a camera at a very restricted specific set of objects, all lit the same way, and all in generally the same basic configuration, you can do some vaguely useful statistics to get some in…
Computer vision is classified under AI in wikipedia. That pretty much sums up what we are trying to arrive at here.
Re: ComputerVisionWiki.org
#9Earlier quoted context omitted.
What do you mean 'work'? There are many highly nontrivial successes in computer vision. Take a look at some of the examples here: http://yann.lecun.com/exdb/lenet/index.html They're pretty surprisingly effective. Or how about melanoma detection and discrimination from benign lesions here: http://scholarsmine.umr.edu/post_prints/00312091_09007dcc803... Or with this thing? http://www.polartechnics.com.au/IRM/Content/pr…
It doesn't work in the sense everybody most wants it to work, which is to slap a cheap CCD camera or three on top of a mobile robot and have it tell the robot everything about its surroundings, like human vision can. Yeah, if you point a camera at a very restricted specific set of objects, all lit the same way, and all in generally the same basic configuration, you can do some vaguely useful statistics to get some in…
It's interesting -- I started writing this exact definition of "works" in my post above. Anthropomorphic bias, right?
Even with this understanding, though, I can't wrap my brain around what you're saying above. Computer vision doesn't "work" (for our definition of "work") because it's not feasible to get enough processing power together:
O( 3e10 ) neurons * 100 Hz/neuron = more cycles than you can rent on an NSF grant.
We've definitely got some exponential growing to do before we can even start meaningful experimentation. Does that mean no work should be done in the meantime?
Re: ComputerVisionWiki.org
#10Could any one suggest a good book on Vision. Something like Cormen for algorithms.
Here are some background and pointers. I'm not a computer vision guy, but these might get you started. Computer vision is really hard . The computational resources we can spend on the problem are orders of magnitude smaller than what we're trying to emulate in the nature. I think (IANACVS!) something like 35% of the human brain's processing capacity deals with vision, for example. So the discipline is both highly mat…
For 4, try Calculus on manifolds, then Differential Geometry (both by Michael Spivak).