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| Gunhee Kim
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01-17-2006 11:39 PM ET (US)
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Edited by author 01-17-2006 11:42 PM
I think the main contribution of this paper is to establish a mathematically plausible model for the elements of early vision based on many psychophysical and physiological evidences. (Am I Right?)
Currently, is Adelsons model one of very plausible hypothesizes or a proven fact? (because this paper is quite old ( Published in 1991.)) Is it true that our visual cells (I'm sorry I'm not familiar with biological terminology) work like a combination of derivative and smoothing functions?
Another fundamental question; how important is it for us (computer scientists) to follow up this kind of research (Cognitive science?) I totally agree that it has been provided us with many good ideas or insights to develop new computer vision algorithms.
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| Stefan Zickler
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01-17-2006 11:58 PM ET (US)
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As a follow-up to Gunhee's question on whether this model really coincides with what living vision cells do: As far as I know, visual cell's activation patterns do in fact at least partially correlate with several of the presented operators of the plenoptic function. Not only has there been psychophysical evidence such as presented in the papers' appendix, but there has also been more recent neuro-scientific evidence which shows similar response patterns as those of plenoptic derivative operators. I remember one particular cognitive science talk where they actually measured life cell activation patterns of a ferret's visual cortex using microwire electrodes. It turns out that the activation pattern really represents basic visual features (such as contrast, orientation). I believe this is the paper matching the talk: http://www.bcs.rochester.edu/people/weliky...n_natural_scene.pdf
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| David Lee
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01-18-2006 02:05 AM ET (US)
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I think plenoptic functions shouldn't be considered as a model for human vision system. They do not describe how the cells work, but rather describe what they can possibly do.
Adelson was clever to find a way to organize low-level features within combination of 2 out of 5 dimensions that can be processed in the early part of the vision system. It would be interesting to watch all of the boxes in his "periodic table" get filled by future researchers. I really do appreciate his work. But as the author pointed out a few times in his paper, there are stimuli (even simple ones) which involve more than 2 dimensions. In that case, his cute 2D squares depicting a stimulus will become cubes in 3D, 4D, ... and it will no longer look cute.
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| Seth Koterba
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01-18-2006 08:41 AM ET (US)
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Edited by author 01-18-2006 08:42 AM
So my understanding of these periodic tables of visual elements is that if we look at a plane defined by two of the dimensions of the plenoptic function, then if there is some response to a particular filter we can find the table associated with that filter and look up what the visual element that caused that response was. Basically it is a mapping from filter responses to visual elements just as Mendeleevs periodic table is a mapping from atomic number, valences, etc. is to the physical elements.
My question, with regard to this idea of periodic table of the visual elements is this: How strong must the response be to consider a particular visual element present? Certainly filter responses are not binary so how do we deal with this gray area when the response is weak? Can a visual element be mmm…kinda there?
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| Matthew
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07-21-2006 04:07 PM ET (US)
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Messages 10-12 deleted by topic administrator between 07-20-2008 02:25 AM and 07-25-2009 02:10 AM |
| darmonrac
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08-16-2008 02:30 PM ET (US)
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cnadronbosi
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08-19-2008 10:14 PM ET (US)
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| warhammer gold
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10-13-2008 03:48 AM ET (US)
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ericbin1
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12-25-2008 12:38 AM ET (US)
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| wow gold
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02-27-2009 09:53 PM ET (US)
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| Aimersoft DVD Creator
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06-13-2009 04:37 AM ET (US)
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06-24-2009 02:55 AM ET (US)
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Deleted by topic administrator 07-25-2009 02:10 AM
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| extract mp3 from youtube
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07-01-2009 09:13 PM ET (US)
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