Skip to main content Accessibility help
×
Home
Hostname: page-component-768ffcd9cc-6vg6l Total loading time: 0.437 Render date: 2022-12-02T20:59:31.537Z Has data issue: true Feature Flags: { "useRatesEcommerce": false } hasContentIssue true
Object Categorization Object Categorization
Computer and Human Vision Perspectives
Buy print or eBook[Opens in a new window]

Book contents

25 - Medial Models for Vision

Published online by Cambridge University Press:  20 May 2010

Sven J. Dickinson
Affiliation:
University of Toronto
Aleš Leonardis
Affiliation:
University of Ljubljana
Bernt Schiele
Affiliation:
Technische Universität, Darmstadt, Germany
Michael J. Tarr
Affiliation:
Carnegie Mellon University, Pennsylvania
Get access

Summary

Medial Representations of Objects

A medial representation of an object describes a locus midway between (at the center of a sphere bitangent to) two sections of the boundary, and gives the distance to the boundary, called the medial radius. The object is obtained as the union of overlapping bitangent spheres. This results in a locus of (p, r), where p gives the sphere center and r gives the radius of the sphere. In some representations, the vectors from the medial point to the two or more corresponding boundary points are included; in others they are derived.

The Blum medial axis is a transformation of an object boundary that has the same topology as the object; thus, the boundary can generate the medial locus (p, r), and the latter can also generate the object boundary. In the first direction the transformation is a function, but in the second direction it is one-to-many, because a medial point describes more than one boundary point. One of the strengths of using the medial representation as a primitive is that any unbranching, connected subset of the medial locus generates intrinsic space coordinates for the part of the object interior corresponding to it. These coordinates include positional location in the medial sheet, a choice of spoke (left or right) and length along that spoke.

Type
Chapter
Information
Object Categorization
Computer and Human Vision Perspectives
, pp. 475 - 487
Publisher: Cambridge University Press
Print publication year: 2009

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Save book to Kindle

To save this book to your Kindle, first ensure coreplatform@cambridge.org is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about saving to your Kindle.

Note you can select to save to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.

Find out more about the Kindle Personal Document Service.

Available formats
×

Save book to Dropbox

To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Dropbox.

Available formats
×

Save book to Google Drive

To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Google Drive.

Available formats
×