Vision Research at Bristol

Vision Research at Bristol Professor David Bull

Head of Visual Information Laboratory

Director Bristol Vision Institute

25 February 2013

What is BVI?

• A grouping of around 35 permanent academic staff and some 70 other researchers at Bristol working on vision and imaging research and its applications

• Adopted by the University of Bristol as a strategic research “Theme” in 2007

• From fundamental psychology and physiology to applications • Learning across disciplines and working across boundaries.

• Collaborators include: BAe Systems, DSTL, BBC, STM, ARRI, Technicolor, Aardman, GDUK, RFEL, Seebyte, QinetiQ, Jaguar, Samsung, Thales, Toshiba, HHI Berlin, ENST Paris, MPI, UCSD, Purdue, RFEL, UNSW, Cambridge, UWE.....

Scope and reach

• Anatomy • Archaeology and Anthropology • Biological Sciences • Biochemistry • BRL • Computer Science • Drama and Film

• Electrical and Electronic Engineering • Experimental Psychology • History of Art • Ophthalmology • Mathematics • Machine Vision Laboratory, UWE • Mechanical Engineering • Medicine

• Answering big questions requires collaboration across traditional academic divides. E.g.:

• To understand and exploit biological systems • To exploit perceptual processes to enhance visual tasks and experiences • To facilitate automation using vision-based methods

Research areas

• Human and Animal Visual

Performance

• Visual Psychophysics

• Vision and Learning

• Visual System Modelling

• Eye Movements and Hand-Eye

Coordination

• Locomotion and vision

• Foraging and mapping

• Robot Vision

• Clinical and Developmental Studies

• Brain Imaging fMRI

• Computational Modelling

• Computer Vision

• Multisensor Fusion

• Detection, Tracking, Classification of

difficult targets

• Search and Retrieval – Finding and

Hiding things

• Camouflage

• Animal biometrics

• Video Compression

• Quality assessment and immersion

• High Dynamic Range imaging

• Immersive video formats

The mantis shrimp

• We are trichromatic: with red, green and blue photoreceptors. The mantis shrimp uses TWELVE colour channels (a world record), PLUS polarisation.

• Coincidentally-perhaps, it also has the fastest and most accurate strike in the animal kingdom....

Visual Information Laboratory

Shared facilities: studio

• RED ONE mysterium • RED EPIC • Sony HDCAM F900 /F500 • Panasonic PTZ • Mikrotron Eosyns (HFR) • Polarisation imager • 24 camera parallel capture • Tobii Eyetracker • Final Cut Pro Mac suite • HD and HFR display • Dolby HDR display • Subjective Evaluation

Shared facilities – locomotion

• HMD with integrated eye tracker • Projection on walls (or screens)

and floor • Qualisys 10 camera motion

capture • Force platforms • Mobile eye tracking • Treadmill

(1) Motion

The motion of a sparse set of features are used to extract 3D pose using

only a single view point. The appearance of the object is not modelled.

Visual SLAM

mapped

points

)t,(R ii

Simultaneously Localise a Camera And Map the environment - SLAM

Applications in Robotics, Wearable Computing, Augmented and Virtual Reality,

and Personal Localisation systems

….in real-time

Visual SLAM demonstration

Anomaly detection

Trajectory-based clustering results:

Animal animation

(2) Enhancing images

Pseudo colouring

Segmentation

– On real images

Conventional level set Conventional level set

Conventional level set Conventional level set

Proposed method

Proposed method

Proposed method

Proposed method

Atmospheric turbulence

Mitigation

And moving targets

(3) Colours and patterns

Reaction-Diffusion-System:

- animals adapt visually to habitats and conspecifics - pattern evolution follows chaotic generation procedures (Turing systems, fractals etc.) - resulting patterns have global properties specific to species - butterfly effect facilitates individually unique patterns

utilization for camouflage & animal identification

Animal biometrics

And not just penguins...

(4) Seeing differences

Con-textures

Con-textures

Graphcut techniques for texture synthesis

Synthesis of textures using a steerable pyramid

Original

Texture

Synthesised

Texture

Compression-texture synthesis

Region

Classification

Segmentation

Texture

Warping

VQA I

Video In

H.264

Encoder

Entropy

Coding

Dynamic Texture

Analysor

Regions

Static

textures

Mo

tio

n

pa

ram

eter

s

Ma

ps

Wa

rped

reg

ion

s

Warping maps

Dynamic textures

VQA II

Synthesised

regions

Synthesis maps

Fee

db

ack

Non-texture

regions

Synthesis-failure

regions

Ch

an

nel

Bit

str

eam

Entropy

Decoding

Texture

MC

Dynamic

Texture

Synthesiser

Warping maps

Motion parameters

Synthesis maps

H.264

Decoder

Reconstructed frames

Reconstructed frames

Wa

rped

fra

mes

Video out

Feedback

Sid

e in

form

ati

on

Parametric coding

Video error resilience

Error Resilience is a Wireless Environment is measured assuming: 2x2 STBC, ½ rate, Constraint length K = 7, convolutional code, Viterbi hard decision decoding, ideal channel estimation and uncorrelated spatial channels, BPSK modulation.

H.264 @56% PER

PVQ @56% PER

(5) Immersive Technology

• The Bristol-BBC Immersive Technology Laboratory has been set up to explore the extended parameter space associated with future immersive video formats – ‘beyond 3D’ • Higher frame rates , Higher dynamic range, Higher resolution • Enhanced colour gamut, Exploiting peripheral vision

Horizontal resolution, pixels

Frame rate (Hz)

2K(HDTV)

4K 8K(SHV)

6K0.7K(SDTV)

50

100

150

200

250

300

350

400

Frame rate required to maintain dynamic resolution of standard definition 50Hz TV without shuttering

Frame rate required to maintain this resolution with 50% shutter

Current proposal for UHDTV2 (SHV) - 120Hz

Contour for systems with sample rate the same as SHV @ 120Hz

HDTV

SDTV

Current proposal forUHDTV1 in ITU-R BT2020 (“4K” Quad HD) – 25Hz

THANK YOU