Article View: comp.lang.prolog
Article #3353Re: Logic Programming and Vision
From: Alan Mackworth
Date: Fri, 20 May 1988 17:09
Date: Fri, 20 May 1988 17:09
40 lines
2805 bytes
2805 bytes
I responded privately on this query but since it has come up it's worth following
up. Ray and I have produced a logical framework for depiction and image interpretation
described in:
R. Reiter & A.K. Mackworth, "The Logic of Depiction"
RBCV-TR-87-18 Dept. of Computer Science, Univ. of Toronto, Toronto, ON, Canada,
also TR-87-24, UBC Dept. of Computer Science, Vancouver, B.C., Canada, 1987.
Abstract
We propose a theory of depiction and interpretation
that formalizes image domain knowledge, scene domain
knowledge and the depiction mapping between the image and
scene domains. This theory is illustrated by specifying
some general knowledge about maps, geographic objects and
their depiction relationships in first order logic with
equality.
An interpretation of an image is defined to be a logi-
cal model of the general knowledge and a description of that
image. For the simple map world we show how the task level
specification may be refined to a provably correct implemen-
tation by invoking model preserving transformations on the
logical representation. In addition, we sketch logical
treatments for querying an image, incorporating contingent
scene knowledge into the interpretation process, occlusion,
ambiguous image descriptions, and composition.
This approach provides a formal framework for analyzing
existing systems such as Mapsee, and for understanding the
use of constraint satisfaction techniques. It also can be
used to design and implement vision and graphics systems
that are correct with respect to the task and algorithm lev-
els.
We transform the specification from FOL+equality to propositional
form so our model theoretic approach has simply an NP-hard problem
(SAT) to deal with. The transformation can be seen as producing
a Constraint Satisfaction Problem. The known algorithms for CSP's
can be seen as approximation algorithms for SAT, in this case.
The natural implementation language for our framework is Prolog.
Alan Mackworth
Technical Details
Message-ID:
<2780@ubc-cs.UUCP>Path:
arc1-ca.pugleaf.net!utzoo!attcan!uunet!husc6!bloom-beacon!bu-cs!purdue!decwrl!labrea!agate!eos!ames!pacbell!att!alberta!ubc-cs!bay.cs.ubc.ca!mackReferences:
<632@hub.ucsb.edu> <2868@cvl.umd.edu>Show Full Headers
Complete Article Headers
Path: arc1-ca.pugleaf.net!utzoo!attcan!uunet!husc6!bloom-beacon!bu-cs!purdue!decwrl!labrea!agate!eos!ames!pacbell!att!alberta!ubc-cs!bay.cs.ubc.ca!mack From: mack@bay.cs.ubc.ca (Alan Mackworth) Newsgroups: comp.lang.prolog,comp.ai Subject: Re: Logic Programming and Vision Keywords: vision research, prolog, logic programming Message-ID: <2780@ubc-cs.UUCP> Date: 20 May 88 17:09:03 GMT References: <632@hub.ucsb.edu> <2868@cvl.umd.edu> Sender: nobody@ubc-cs.UUCP Reply-To: mack@bay.cs.ubc.ca (Alan Mackworth) Organization: UBC Department of Computer Science, Vancouver, B.C., Canada Lines: 40