[comp.archives] [neural-nets] Re: NNs in 2D shape recognition

ins_atge@jhunix.HCF.JHU.EDU (Thomas G Edwards) (05/14/91)

Archive-name: ai/neural-nets/zemel-unsup-recog/1991-05-13
Archive: cheops.cis.ohio-state.edu:/pub/neuroprose/zemel.unsup-recog.ps.Z [128.146.8.62]
Original-posting-by: ins_atge@jhunix.HCF.JHU.EDU (Thomas G Edwards)
Original-subject: Re: NNs in 2D shape recognition
Reposted-by: emv@msen.com (Edward Vielmetti, MSEN)


In article <1991May12.115515.7741@comp.vuw.ac.nz> Conrad.Bullock@comp.vuw.ac.nz (conrad Bullock) writes:
>Greetings.
>I am working on an honours project, aiming to apply neural networks to
>recognising simple shapes in two-dimensional space, independent of
>position, noise, rotation, magnification, and other transforms.
>Does anyone have any good references in relevant work, particularly in
>rotation-invariant recognition?

Get Zemel and Hinton "Discovering Viewpoint-Invariant Relationships
 That Characterize Objects" from the /pub/neuroprose dir of
 cheops.cis.ohio-state.edu via anon ftp.

Two networks are trained on images of the same object with various
orientations, positions, and sizes.  The networksd are trained to
have high mutual information between their four outputs, which
if properly trained must represent a coding of the orientation,
position, and size of the of the object.  While extracting that recoding
might not be easy, we can use this property to have a network
trained in this way reject other shapes it is exposed to since the
outputs will no longer agree on the position, orientation, and
size of the object. Thus multiple nets trained in this way can
compete and see which pairs have the highest mutual information.
The pair which has the highest mutual information will be the
pair trained on the shape of the test object.

-Thomas Edwards

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