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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

#41

Post by cropher »

cheschire wrote: post #2

I have a different hypothesis. I think line drawings are the representation of vectors. The details we focus on are the vectors with the highest magnitude of change, but that change is not always visual. For example, momentum often has an outsized representation in line drawings. Edges can be a high magnitude change as well, but it's not the only thing.

Interesting; can you elaborate? Also could you clarify what you mean by changes that are "not always visual"? How would non-visual information exist in a purely visual medium?

Re: Edge detection doesn’t explain line drawing

#42

Post by mjburgess »

pavlov wrote: post #16
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…

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.

Reasoning by analogy is one of the ways we solve the framing problem.

So, when explaining the universe we imagine it's an act of will by a conscious entity (ie., like how we invent). When explaining the mind we suppose it's like one of our inventions.

Absent an analogy of some kind it's quite hard to determine what features are salient. Objects have an essentially infinite number of properties.

Re: Edge detection doesn’t explain line drawing

#43

Post by Nevermark »

The article sheds doubt on edge detection as being the major reason why we can interpret drawings as what they attempt to portray, because drawings are often missing shading and color.

Drawings also often drop a great amount of detail, and proper proportion information, and remain recognizable.

Think of cave paintings or Picasso’s bull.

But if you consider image interpretation as a competitive classification, then missing information doesn’t present a problem.

If color, shading, detail & proportion are missing, then they are missing from all possible pattern interpretations equally. That leaves the final classification problem relatively unchanged despite all the missing info.

EDIT: in fact, if my hypothesis is true we should be able to see patterns with even less information!

For instance, dropping all internal detail, and even most shape. As in seeing a face profile on the side of a cloud that otherwise looks nothing like a human head.

Or dropping edges completely. Perhaps seeing an object where there are only stars creating points of light.

Please post your anecdotal experiments at 404experimentreports.com!

Re: Edge detection doesn’t explain line drawing

#44

Post by civilitty »

krisoft wrote: post #39
CuriouslyC wrote: post #20

Earlier quoted context omitted.

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 co…

> I seriously think that it is within the realm of possibilities that this universe we live in (including us) is a literal simulation.

Notice how you dropped the “computer” part. Without that qualifier, the “universe is a simulation” hypothesis goes back at least to Descartes and his evil demon [1].

That’s the GP’s point. The “demon,” “clockwork,” and “computer” are just metaphors to help illustrate the point. Hundreds of years ago it was a trickster demon, now it’s computers - the simulation part is the same.

(The world floating on a turtle idea traces to the world turtle and several different creation myths, so it’s safe to say their believers took them a bit more literally)

[1] https://en.m.wikipedia.org/wiki/Evil_demon

Re: Edge detection doesn’t explain line drawing

#45

Post by cvoss »

The brain's ability to do "shadow removal" is really impressive. You can see it happening in the final example depicted in the article. I think this ability is what was used to explain "the dress". It also comes up in a classic optical illusion [0] where a checkerboard of light and dark gray squares has an object sitting on it and casting a shadow. The shadowed light gray squares are exactly the same shade as the unshadowed dark gray squares, but if you point this out to someone, they'll have a really hard time accepting it because they are so good at unconsciously accounting for shadows.

[0] https://en.wikipedia.org/wiki/Checker_shadow_illusion

Re: Edge detection doesn’t explain line drawing

#46

Post by waitwhathu »

krisoft wrote: post #39
CuriouslyC wrote: post #20

Earlier quoted context omitted.

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 co…

[flagged]

Re: Edge detection doesn’t explain line drawing

#47

Post by civilitty »

HPsquared wrote: post #38
bregma wrote: post #32

Earlier quoted context omitted.

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.

Abstract algebraic equations are not closer to biology than the steam engine or clockwork watch.

The latter are at least physical. Gradient descent and inference doesn’t resemble the physical mechanisms that drive neurons at all. Floats and integers aren’t even capable of representing a continuous voltage potential.

Re: Edge detection doesn’t explain line drawing

#48

Post by bduffany »

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…

The "Problem #2" that they mention also has an easy solution.

If the "intermediate" variable / internal representation is just "the input image but with edges only," then of course you can see internal representations.

When you compute that intermediate variable for the line drawing, it will just happen to behave like the identity function for that particular case. So if you have already filtered out non-edges then the transformation is basically a no-op.

The "types" mismatching as they mention is not a concern because the type is just "image" i.e. a big vector of HSL values or something. Edge detection is just a convolution filter so it's going to have approximately the same type as the input.

Re: Edge detection doesn’t explain line drawing

#49

Post by cheschire »

cropher wrote: post #41
cheschire wrote: post #2

I have a different hypothesis. I think line drawings are the representation of vectors. The details we focus on are the vectors with the highest magnitude of change, but that change is not always visual. For example, momentum often has an outsized representation in line drawings. Edges can be a high magnitude change as well, but it's not the only thing.

Interesting; can you elaborate? Also could you clarify what you mean by changes that are "not always visual"? How would non-visual information exist in a purely visual medium?

The example I mentioned was momentum. That's not visual information, that's extrapolated information of position over time. It can be represented in line drawings as motion lines in comics, for example. Interestingly, by simply implying motion, I hypothesize that the brain deprioritizes processing detail on the object that is implied to be moving, and focuses instead on the interactions that will follow.

If I were a researcher, my contrived test of this would be to simply have people recreate drawings of "static" objects, and have others recreate drawings of objects implied to be in motion.

Other non-visual information would be emotions. The shape of eyes and mouth lines are highly critical to passing emotion. I suspect that people's interpretation of emotion directly impacts how strong the emotional representation of those parts of the face would be drawn. For example if a test subject is told to draw the face of a model in front of them, but they are told the person is experiencing an emotion, I hypothesize that the group of people who are told the person is happy would more frequently bias their interpretation of the eyes, eyebrows, and corners of the mouth towards a "happy" representation than those who are told the person is experiencing great inner turmoil.

To be clear though, I'm not saying we only draw based on non-visual information. I'm saying the sum total of all vectors has an influence on the drawing. Colors, in my opinion, have as much of an impact as edges. And it would be interesting to compare the drawings of a person with less common color sensitivities to more common color sensitivities.

Re: Edge detection doesn’t explain line drawing

#50

Post by mistercow »

Are there any studies on what, if any, animals respond to line drawings (and to what extent)? In particular, do chimpanzees and other apes closely related to humans?

It seems somewhat plausible that “lines-as-edges” was a foot in the door for something that specifically evolved in humans as our ancestors began using paintings and drawings for communication. Maybe it was initially just hijacking edge detection so that some images could be conveyed through drawings, and over time, and that developed into a kind of “grammar” for artificially depicting more nuanced images in media where realism was impossible.

This would be similar to how recognizing and interpreting different kinds of basic vocalizations (as many animals can) developed into a much more sophisticated mechanism for developing complex language.

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