Computer Vision Introduction

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Introductory Techniques for 3D Computer Vision. Prentice-Hall, 1998. □. R. Szeliski. Computer Vision. Springer .... Algorithmic. □. Implementative. (hardware ) ...
Computer Vision Introduction Andrea Torsello [email protected]

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Getting in contact 

Student -> Teacher [email protected]



Teacher -> Strudents 

course web site http://www.dsi.unive.it/~atorsell/Visione

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Texts 







R. C. Gonzalesz and R. E. Woods. Digital Image Processing. Prentice-Hall, 2002 D. Forsyth and J. Ponce. Computer Vision. A Modern Approach. Prentice-Hall, 2002 E. Trucco and A. Verri. Introductory Techniques for 3D Computer Vision. Prentice-Hall, 1998 R. Szeliski. Computer Vision. Springer 2011.

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Goals What does it mean to see? Computer vision: Build a system that “sees”

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Related Fields 

Image processing



Pattern recognition (Machine learning/Data mining)



Scene analysis

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Image Processing

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Pattern recognition

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Scene Analysis

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Taxonomy High/Medium/Low level vision 

Low 



input=image, output=image

Medium 



(image restopration, contrast enhancement, …):

input=images, output=attributes/features

High 

(segmentaion, shape recogntition, …):

(Image analisys, scene understanding, …):

input=images, output=concepts

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Some applications of Computer Vision

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Image search

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Face Detection

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Face Recognition

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Robotics

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Surveilance

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Driving Assistance

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Autonomous Vehicles

Tartan racing

(Carnegie Mellon University, General Motors Corporation, Caterpillar, Continental e altri)

vinctori DARPA Urban Challenge 2007 Computer Vision - Introduction

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Satelite surveys 



Stereo reconstruction of the surace of Venus from a pair of satelite images (Institute for Computer Graphics and Vision, Technical University of Graz, Austria)

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Medical Image Analysis

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Digitalization

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Digital Photography

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Cinema & TV

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Some Hystory 

Emissionist theory (tactile vision) 

The eye emits rays that travel through space and hit objects. The contact of the ray and the objects causes the visual sensation. 



Intromissionist theory 

Object continuously emit to the surounding space imaeges of them selves. This images (eidola) enter the eye throught the pupil, thus revealign themselves. 



Pythagoras, Empedocles, Euclid

Democritus, Epicurus, Lucretius

Persistence of retinal images (“after-image”) 

Ibn al-Haytham (Alhazen) (965-1039 AD)

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Keplero and the theory of retinal images



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1604 Kepler develops the modern theory of retinal images.

Perception as unconscious conclusions Helmholtz

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Recent models... 



James J. Gibson (1904-1979) and the ecologic approach “The belief of the empiricists that the perceived meanings and values of things are supplied from past the experience of the observer will not do. But even worse is the belief of nativists that meanings and values are supplied from the past experience of the race by innate ideas.” (Gibson, 1979)

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David Marr and the computational approach Three levels: 

Computational



Algorithmic



Implementative (hardware)

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Illusions

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Ames' room

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Necker Cube

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Bistable images



Jastrow duck/rabbit

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Contextual perception of length 

Mueller-Lyer illusion

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Ponzo illusion

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Fraser Spiral

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Escher's impossible images

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Bottom-up or Top-down?

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Bottom-up or Top-down?

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