Liz Marai 07/31/08 1

Graphics and Visualization

Liz MaraiSENQ 5423

Liz Marai 07/31/08 2

Computer Graphics

• Computer graphics generally means creation, storage and manipulation of models and images

• Such models come from diverse and expanding set of fields including physical, mathematical, artistic, biological, and even conceptual (abstract) structures

Frame from animation by William Latham, shown at SIGGRAPH 1992. Latham uses rules that govern patterns of natural forms to create his artwork.

Liz Marai 07/31/08 3

Liz Marai 07/31/08 4

Simulating the Air Flow around a Bat Wing

Liz Marai 07/31/08 5

Visualization• branch of computer graphics that is concerned with presenting data to users,

by means of images, with the goal of improving understanding of the data being presented.

• relatively new field (1983)

• draws people w/ an interest in: – computer graphics/computer vision, medical imaging,…

– data mining, cognition science,…

– application-specific sw systems,…

Liz Marai 07/31/08 6

Scientific and Information Visualizationvisualization of an extremely large simulation of the instability caused by two mixing fluids http://

www.llnl.gov

visualization of human development http://tools.google.com/gapminder/

Liz Marai 07/31/08 7

(medical measurements)

insight

Modeling anatomical joints

data Computational & analysis tools

models

simulations

Liz Marai 07/31/08 8

Impact

• Help plan surgical interventions and therapy

• High-performance robots and implants

• More realistic computer animations [Tony de Rose, Pixar]

Liz Marai 07/31/08 9

Tracking motion: ideaextract bone outline from one volume image (CT scan)

track outline through sequence of volume images (1990)

(not too many sample poses – radiation concerns)

Liz Marai 07/31/08 10

Computational modeling: joint-spacing and cartilage (Marai et al, EMBC'06)

Idea: cartilage correlates with bone proximityparameter: p the proximity threshold

Liz Marai 07/31/08 11

Scaphoid bone

7 poses

@ 2mm p

Bone in blue, cartilage in tan

Cartilage maps: location results

Liz Marai 07/31/08 12

Applications:Push-up

DRUJ malunion

Liz Marai 07/31/08 13

The push-up debate (Alexis vs. Crystal)

• on your knuckles or not?

Liz Marai 07/31/08 14

The push-up debate (Crystal wins)

• CT volume images of one individual• 7 different poses (knuckle-pose included)• computed cartilage contact & ligament lengthening in

each pose• ~48 hrs, single processor• knuckle pose yields maximum contact

Liz Marai 07/31/08 15

The push-up debate: knuckle-walkers

Liz Marai 07/31/08 16

Applications:Push-up

DRUJ malunion

Liz Marai 07/31/08 17

DRUJ malunion

Distal radioulnar joint (DRUJ)

Liz Marai 07/31/08 18

DRUJ malunion (Crisco et al, JOR’07)

Liz Marai 07/31/08 19

Contact

• http://vis.cs.pitt.edu• marai@cs.pitt.edu• SENQ 5423