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Edge detection doesn’t explain line drawing

aaronhertzmann.com

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Re: Edge detection doesn’t explain line drawing

#31

Post by HPsquared »

hprotagonist wrote: post #8
cnity wrote: post #3

As someone (probably like many here) who graduated from a university which taught computer vision and peripheral neuroscience courses, with such titles as "Computational Neuroscience of Vision", I always felt that trying to understand the human brain as a kind of algorithm was a bit of an artefact of computer scientists as they approach biology. The truth is the visual cortex is vast, and not sufficient to explain th…

ah, someone who paid attention in lecture! (incidentally; there’s a fairly deep literature of historians of science that have carefully documented that we describe ourselves as analogous to the most sophisticated technology of the day: see “to lose one’s temper”, “to blow a gasket”, “i got my wires crossed”, “sorry, cache miss”, … as metaphors and idioms of mental state through the centuries that reflect the cool tec…

Now the technology is starting to reflect the biology (neural networks). Inception!

Re: Edge detection doesn’t explain line drawing

#32

Post by bregma »

HPsquared wrote: post #31
hprotagonist wrote: post #8

Earlier quoted context omitted.

ah, someone who paid attention in lecture! (incidentally; there’s a fairly deep literature of historians of science that have carefully documented that we describe ourselves as analogous to the most sophisticated technology of the day: see “to lose one’s temper”, “to blow a gasket”, “i got my wires crossed”, “sorry, cache miss”, … as metaphors and idioms of mental state through the centuries that reflect the cool tec…

Now the technology is starting to reflect the biology (neural networks). Inception!

Give two very different things the same name and soon enough many people will believe them to be the similar in nature.

If you repeat the lie often enough if will become the truth.

Re: Edge detection doesn’t explain line drawing

#33

Post by HPsquared »

adolph wrote: post #21
hprotagonist wrote: post #8

Earlier quoted context omitted.

ah, someone who paid attention in lecture! (incidentally; there’s a fairly deep literature of historians of science that have carefully documented that we describe ourselves as analogous to the most sophisticated technology of the day: see “to lose one’s temper”, “to blow a gasket”, “i got my wires crossed”, “sorry, cache miss”, … as metaphors and idioms of mental state through the centuries that reflect the cool tec…

I think in the case of “to lose one’s temper”, there isn’t an obvious match between the technology of the day and the early medical theory of four humours, not of metal-working. Origin of Temper, New Oxford American Dictionary: Old English temprian 'bring something into the required condition by mixing it with something else', from Latin temperare 'mingle, restrain'. Sense development was probably influenced by Old F…

So tempered steel is well-balanced steel, or mild-mannered.

See also the well-tempered clavier. In music, the temperament is an aspect of the tuning system relating to how the dissonances of different notes are balanced.

Re: Edge detection doesn’t explain line drawing

#34

Post by heavenlyblue »

simias wrote: post #9

Ten years or so ago I was working on a video chip that had an upscaler feature. While prototyping and simulating it, we first started by applying a mathematically-correct (i.e. information preserving) FIR filter to do the upscale. Then we compared the result with other solutions and found that ours looked worse. We asked our colleagues to blind-test it and they all picked third-party-scaled images over ours. At first…

Surely if you're upscaling pixel art you're loosing information when you create gradients between pixels. It doesn't seem to me that your metric of information loss was ideal.

Re: Edge detection doesn’t explain line drawing

#35

Post by coldtea »

empath-nirvana wrote: post #24
coldtea wrote: post #18

> A classic answer to this question is what I will call the Lines-As-Edges hypothesis. It says that drawings simulate natural images because line features activate edge receptors in the human visual system. Why does the explanation need to go to that direction? Line drawings have a liking to the thing being depicted. They're a crude representation of it (compared to a photograph or a photo-realistic oil painting) but…

People are so used to seeing images that it's impossible to recognize that they're an _illusion_. If you see a drawing of an apple, it is colored pigment on a page, it's not an apple, but it's _impossible_ to look at it and not see an apple. _Why_ do we recognize it as an apple? It's certainly not an exact duplicate of the light rays that would enter your eye from a real apple. How different can it be from an apple a…

>Calling an image a "representation" or saying that it "has a liking" to the real thing is sort of begging the question. The question to be answered is: "In what way is it a representation?

Represenation or having-a-liking is not some hazy notion though. It means there are things in our drawing that map to how those things are in the actual thing. And there are: edges, proportions, shapes.

But it's not some close mapping of edges in the literal sense. That is, a drawing doesn't have to follow the actual edges of the thing depicted with any accuracy for it to be recognized as such.

E.g. we could draw a stick figure instead of a detailed line drawing of a person, or a highly stylized "child drawing" style house, and their edges would look nothing like the edges of the real thing's. But those line drawings would still be easily recognizable.

Re: Edge detection doesn’t explain line drawing

#36

Post by CapsAdmin »

bschne wrote: post #17

> Problem #1: What about all the other features? Is this necessarily a problem in the argument? If we consider e.g. color, and construct a blurry image that has a color distribution very similar to a real face, but doesn't fire the edge detection in the same way, we can still recognize it as a face. This could just mean that a sufficiently close match to other examples of the same class on any one of the strong "dime…

This stood out to me as well. If I close my eyes and walk into a wall I will still perceive the wall.

Our various senses help build an understanding of what's going on. It's not like we fail to understand anything once you remove one part of the system.

Maybe this person is trying to say something deeper or more nuanced and I fail to understand the meaning behind it.

Re: Edge detection doesn’t explain line drawing

#37

Post by Kinrany »

simias wrote: post #9

Ten years or so ago I was working on a video chip that had an upscaler feature. While prototyping and simulating it, we first started by applying a mathematically-correct (i.e. information preserving) FIR filter to do the upscale. Then we compared the result with other solutions and found that ours looked worse. We asked our colleagues to blind-test it and they all picked third-party-scaled images over ours. At first…

The upscaled image stores more information than the original image, so it must be possible to keep all the information while still doing edge enhancement!

Re: Edge detection doesn’t explain line drawing

#38

Post by HPsquared »

bregma wrote: post #32
HPsquared wrote: post #31

Earlier quoted context omitted.

Now the technology is starting to reflect the biology (neural networks). Inception!

Give two very different things the same name and soon enough many people will believe them to be the similar in nature. If you repeat the lie often enough if will become the truth.

Not really a lie, just biomimicry. The full name is "artificial neural network" after all.

It's a lot closer to biology than the steam engine or clockwork watch.

Re: Edge detection doesn’t explain line drawing

#39

Post by krisoft »

CuriouslyC wrote: post #20
pavlov wrote: post #16

Earlier quoted context omitted.

And also the universe itself is often seen through the lens of contemporary technology. Are we living on an island that floats on a giant turtle’s back? Or are the heavens like giant clockworks? Or maybe it’s all a computer simulation? These cosmological speculations are separated by thousands of years, but they are all simply a reflection of what the person finds most awe-inspiring in their everyday life.

The difference is turtles all the way down was literal, but heavenly clockwork and computer program perspectives are clear metaphors.

> turtles all the way down was literal

Was it? What evidence do you have for that? If anything it sounds like the kind of verbal slapdown someone in authority would subject someone trying to be a smart alec. It is short. Easy to understand. And closes the kind of questioning.

I would be very surprised if someone have considered it the literal truth, but of course have seen stranger things.

> heavenly clockwork and computer program perspectives are clear metaphors.

I don’t know about the clockwork. You will need to find someone who talks about that and ask them if they meant as a metaphor or not.

On the other hand I know about the computer simulation one. That for me is not a metaphor. I seriously think that it is within the realm of possibilities that this universe we live in (including us) is a literal simulation.

There would be possible physical experiments which depending on their results could make me increase or decrease my confidence in that statement. But I don’t consider it a metaphor.

Now of course that is only the viewpoint of a single human, at a single point of time. So it might not matter much. But it shows that it is not that “clear” that everyone considers that view only as a metaphor.

Re: Edge detection doesn’t explain line drawing

#40

Post by empath-nirvana »

coldtea wrote: post #35
empath-nirvana wrote: post #24

Earlier quoted context omitted.

People are so used to seeing images that it's impossible to recognize that they're an _illusion_. If you see a drawing of an apple, it is colored pigment on a page, it's not an apple, but it's _impossible_ to look at it and not see an apple. _Why_ do we recognize it as an apple? It's certainly not an exact duplicate of the light rays that would enter your eye from a real apple. How different can it be from an apple a…

> Calling an image a "representation" or saying that it "has a liking" to the real thing is sort of begging the question. The question to be answered is: "In what way is it a representation? Represenation or having-a-liking is not some hazy notion though. It means there are things in our drawing that map to how those things are in the actual thing. And there are: edges, proportions, shapes. But it's not some close ma…

> That is, a drawing doesn't have to follow the actual edges of the thing depicted with any accuracy for it to be recognized as such

This is literally what this link is about, but you do still recognize that there is are "why" and "how" questions to be answered here?

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