Computational Perception Li Liu

Course• 10 lectures

• 2 exercises

• 2 labs

• 1 project

• 1 written examination

Scope

Biomedia

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Computational Perception

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What Do We Study?

• to learn how perceptual organs work

• to understand information processing under nervous systems

• to experience technical challenges

Perceptual Process

Perceptual Process

Sensation Perception Cognition

Proximalstimulus

DistalStimulus

processingTransduction Recognition ActionPerception

Perceptual Cycle

A: The behavior approach stimulation to perception

B: The physiological approach stimulus to processing

C: The psychological approach processing to perception

D

D: Our approach Transduction to perception

Course Focus

Transduction processing Perception

Lec 6 Perceptive field Lec 7 Sensory integrationLec 9 Visual attentionLec 10 Tactile video

Lec 3 Neuron, neural network, and brainLec 5 Learning and neural networks

Lec 4 Natural Sensors

TransductionTransduction is the transform of one form of energy into another form of energy. In the nervous system, transduction occurs when environmental energy is transformed into electrical energy.

Perceptual OrgansTransduction is the transform of one form of energy into another form of energy. In the nervous system, transduction occurs when environmental energy is transformed into electrical energy.

Neural ProcessingNeural processing is the operations that transformthe electrical signals in the networks of neurons. An important processing is to extract the primary sketches from sensory raw data.

Right Eye

Left Eye

Retinal Image

Superior Colliculus (left lobe)Lateral

Geniculate Nucleus (LGN) - left Optic Radiations

Visual Association Cortex

Optic Nerves

Optic ChiasmOptic Tracts

Perception

Perception is the process of putting inputs together into a usable mental representation of the world.

Information Rate

sensation perception cognitiondata information knowledge

CognitiveBandwidth

PerceptualBandwidth

SensoryBandwidth

How Do We Study Perception?

This course is to understand information processing in the nervous system.

• computer simulations of neural circuits, models of learning, • representation of sensory information in neural networks, • computational analysis of problems in biological sensing and perception

Three Topics

• Learning in neural network• Interaction bwteen our neural system and physical environment• Sensory integration

How To Do A Project?

Li Liu

Research & Project

” The good researcher is not ’one who knows the right answers’ but ’one who is struggling to find out what the right questions might be’ ”

Phillips and Pugh, 1994

1. Setting your project

2. Conducting your project

3. Presenting your project

Project

1. Setting your project

• Writing a proposal

• Project planning

Writing a project proposal

• Thinking about

Title, aim, objectives, extected outcomes, related research, questions, hypotheses,

methods, .....

Project Planning

• Work breakdown

• Time estimates

• Milestone identification

• Activity sequencing

• Scheduling

• Replanning

2. Conducting your project

• Literature searching and literature reviews

• Doing your project

Literature review

To avoid ”re-invent wheel”

Doing your project

• Project Control

• Dealing with problems

• Managing your time

• Using your supervisor

• Team work

3. Presenting your project

• Writing report

• Oral presentation

Ref:

The Essence of Computing Projectsa student’s guide

by Christian W. Dawson

Good luck!

What is a ”project”?

Project = ”Solving a problem”

A Problem?

• What is the problem?

• How to solve the problem?

• How to know that the problem has been solved?

• How good is the solution? A quality measure.

Case 1

Personal Area Network

Principle

Speech – Control Technology

Name Dialing

Hand Free

Speech Recognizer

SpeechRecognizer

”repeat”

Speech Signal Waveform

Effect of Background Noises

Performance

Speech-to-Noise Ratio (dB)

Word

s C

orr

ect

Rate

(%

)

-30 0

100

0

Lip Tracker

Performance of Speech Recognition

Speech-to-Noise Ratio (dB)

Word

s C

orr

ect

Rate

(%

)

-30 0

100

0

Auditorycues only

Auditory andvisual cues

How to Design A Headset?

Tip ?

Mobile Phones

Scenario• Shadi has a banking system based on a password• He heard about an old Palestinian-Chinease identification system that could increase his system security• He made a search on the Internet and found that he may find it at Umeå University, Biomedia2007.• You are the consultants to help him

How to enjoy football with your mobile phone

One way is to use animation..

Live Experience!

Vibration

What is the ball?

What is the ball?

Information Transform!

Control Patterns

Task

To develop and evaluate a touch-based footballbroadcasting system for mobile users

iPhone

Virtual Buttons

Real Buttons vs Virtual Buttons

”Entry speed and error rate”

Task

To add the tactile cues of real buttons to virtualbuttons displayed on mobile devices with touch screens.

Why Do We Study Perception?

To upload information to our brain!

Direct Interface

Speech Recognizer

Implantable ChipsImplantable Chips

Neural-Silicon Interface

Implantable Computing

Sensory IntegrationSensory Integration

Resolution of RF

On-Off Perceptive FieldOn-Off Perceptive Field

Mathematical Models of Perceptive Fields

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exp()2(2

1),(

2

22

2

22

42

σ

yx

σ

yx

πσyxG

)]22

2exp(

2

1[)]

22

2exp(

2

1[)( ,

iσ

x

eπσeσ

x

πiσeσDOGσ

Function of Perceptive Fields

Image Analysis

Neural Information Transmission

Switch Circuits