Some Questions ...

[Deshpande]

Dear Members,
 
  We are currently working on a symbolic approach to low level
processing of visual information. There may be many researchers
in this list who might be working in this area of vision. I would like
to pose certain very basic questions whose importance was often overlooked.

  Let me first in simple terms put forth the problem that we working on:
Is the information processing in low level vision symbolic or non-symbolic?
That is, should the signal that the measurement devices capture be 
interpreted symbolically or , as conventionally being followed, 
in the functional domain. And what are the implications of the two 
initial forms of representation as far as pattern recognition is considered?
Some of the related work can be found in [1]. Moreover,

1) What is the justification for a spatial/frequency domain decomposition
   of the signal (intensity-map) that is representing the objects ?

2) Through an information theoretic point of veiw, what relevance does this
   decomposition have ?

3) Neurophysiological evidence does show a similarity to  a Gabor
   filtering scheme in the human visual system , but as David Marr had
   rightly pointed out, how does this help one to understand 
   its specific relationship to perception ?

4) Even if one assumes an ad hoc justification for the above (spatial-
   frequency based decomposition),  how does one justify the distance 
   function imposed on the vector space formed by these basis functions 
   (of gabor filters), that is, how does this distance function bring out
   the relationship between the geometrical information of objects that the 
   signal is representing?

One finds a lot of literature on this approach of spatial-frequency
domain decompostion of the signal as a scheme for texture segmentation,
but none really justifies the appropriateness of this approach.

If the above is not of relevance to the majority of the members please
send your suggestions and comments directly to the following email address:
d23d at unb.ca .


cheers,

      sanjay 


[1] I.B.Muchnik and V.V Mottl, "Linguistic Analysis of Experimental Curves",
    Proc. IEEE, vol 67, no. 5, May 1979.