From 9f3f85ae2f80d4b1825cc0feda0ef9f8e1e27f97 Mon Sep 17 00:00:00 2001
From: Michael Biggs <mbiggs@csclub.uwaterloo.ca>
Date: Tue, 15 Jun 2004 18:03:30 +0000
Subject: [PATCH] Added Richard Mann's talk.

---
 events.xml | 34 ++++++++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)

diff --git a/events.xml b/events.xml
index 317d74f..af522cc 100755
--- a/events.xml
+++ b/events.xml
@@ -1,6 +1,40 @@
 <eventdefs>
 <!-- Spring 2004 -->
 
+  <eventitem date="2004-06-17" time="4:00 PM" room="MC 2066"
+   title="``Optical Snow'': Motion parallax and heading computation in densely cluttered scenes. -or- Why Computer Vision needs the Fourier Transform!">
+   <short>A talk by Richard Mann; School of Computer Science</short>
+   <abstract>
+    <p>
+When an observer moves through a 3D scene, nearby surfaces move faster in the
+image than do distant surfaces.  This effect, called motion parallax, provides
+an observer with information both about their own motion relative the scene,
+and about the spatial layout and depth of surfaces in the scene.
+    </p>
+    <p>
+Classical methods for measuring image motion by computer have concentrated on
+the cases of optical flow in which the motion field is continuous, or layered
+motion in which the motion field is piecewise continuous.  Here we introduce a
+third natural category which we call ``optical snow''.  Optical snow arises in
+many natural situations such as camera motion in a highly cluttered 3-D scene,
+or a passive observer watching a snowfall.  Optical snow yields dense motion
+parallax with depth discontinuities occurring near all image points.  As such,
+constraints on smoothness or even smoothness in layers do not apply.
+    </p>
+    <p>
+We present a Fourier analysis of optical snow.  In particular we show that,
+while such scenes appear complex in the time domain, there is a simple
+structure in the frequency domain, and this may be used to determine the
+direction of motion and the range of depths of objects in the scenes.  Finally
+we show how Fourier analysis of two or more image regions may be combined to
+estimate heading direction.
+    </p>
+    <p>
+This talk will present current research at the undergraduate level.  All are
+welcome to attend.
+    </p>
+   </abstract>
+  </eventitem>
   <eventitem date="2004-05-26" time="5:30 PM"
    room="DC 1350" title="Computing's Next Great Empires: The True Future of Software">
    <short>A talk by Larry Smith</short>