Here is a link to the slides from Andrew Blake's fascinating presentation last night on Computer Science and Illusion. (44MB, zipped PPT) 

His presentation took us on a journey through four topics from computer vision: perspective drawing, texture, shading, and his current interest, stereo projection.  For each topic, we progressed from visual illusions (such as ambiguity, or impossibility, as is the case with this Swedish stamp), through theories that have arisen from analysing those illusions, to algorithms which implement aspects of those theories and are being used to further computer vision research. 

In some cases, the ideas he presented have broken free of the Microsoft Research lab and found their way into products, such as Digital Image Suite and the upcoming Expression Graphic Designer.  Others, such as the stereo webcamera he called TwoCam (pictured here), are bursting to make that leap, with plenty of potential applications.

Professor Blake is a rare combination - he is "that guy" who has make immense contributions to his field, but he can also explain computer vision in a way that makes it approachable and relevant.

Speaking of relevant, see the introductory section of his book Active Contours for a list of ten diverse real-world applications for computer vision, from the obvious (traffic monitoring, robot grasping, medical diagnosis), to the sublime (automatic crop spraying, automated video editing).

That introductory section also provides an overview of a few fundamental computer vision techniques, not least of which is one that involves the slithering of snakes on a plane.*

The IrishDev crew was out at Trinity in full effect, armed to the teeth with video and audio recording equipment.  I look forward to linking to their recording of the talk!

* Active contours on a planar surface, that is :)