[Colloquium] Osadchy talk - Tues. Feb. 17th 2:30 at TTI

[Meridel Trimble]

TOYOTA TECHNOLOGICAL INSTITUTE TALK 

Speaker: Margarita Osadchy
NEC Labs

Speaker’s homepage: http://www.cs.haifa.ac.il/~gamer/

Time: 2:30pm
Date: Tuesday, February 17th
Place: TTI-C (1427 E. 60th St. – Press Building)
*REFRESHMENTS PROVIDED*

Title: Illumination Insensitive Methods of Visual Comparison

Abstract: Image comparison is a fundamental component in many computer vision 
tasks such as recognition, alignment and tracking. Variation in lighting is 
critical to image comparison, because it dramatically affects the appearance 
of an object in an image. Current methods approach this problem by focusing on 
effects created by discontinuities in matte objects, which are insensitive to 
lighting changes. However this approach is very limited because it treats 
other effects as unmodeled noise, including the effects of smooth, untextured 
surfaces and the effects of shiny objects that produce significant highlights. 
These are present in most real objects. I show that these properties can be 
modeled, and they provide a rich source of information. I tackle the problem 
presented by smooth surfaces with no edges or texture by using a whitening 
tool from signal processing theory to design a superior measure of image 
comparison. This can provide a component in a general comparison method that 
also integrates past approaches. Recognition of shiny objects is also very 
challenging, since the appearance of the highlights they produce changes 
drastically with the viewing conditions. I show that using a simple 
qualitative model of specular reflection I can judge the consistency of 
specularities with 3D object geometry and use this consistency to identify 
very challenging transparent objects such as wine glasses. Next, I integrate 
this knowledge about the highlights with previous methods for matte objects. 
This allows recognition of glossy, smooth objects, such as pottery, which are 
very challenging for existing methods.
  
If you have questions, or would like to meet the speaker, please contact 
Meridel at 4-9873 or mtrimble at tti-c.org 
  
For information on future TTI-C talks or events, please go to the TTI-C Events 
page: http://www.tti-c.org/events.shtml