GLYPHS IN LAYERED 2D MEDICAL VISUALISATIONS

Simon Walton

THEMES

• Glyphs in medical visualisation, generally

• Combining glyphs with other types of visual representations

GLYPHS IN MEDICAL VIS

• Glyphs in both research and clinical settings

• Clinicians still want numbers

• Perceptual bias is an issue

• Large variance in accuracy of perception

• Laying out glyphs can be an issue

POSITIONING GLYPHS

• Do we allow overlaps?

• What is the significance of each glyph’s position?

• Strategies (Ward)

• Data-driven

• Structure-driven

POSITIONING GLYPHS

OTHER CONSIDERATIONS

• Do we want some glyphs to pop out?

• Can emphasise using visual perception theory

• What parameter mapping function is used?

• Continuous or discrete?

DIFFUSION TENSOR IMAGING

Eigenvectors

Ellipse

DIFFUSION TENSOR IMAGING

DIFFUSION TENSOR IMAGING

CMR VISUALISATION

CMR VISUALISATION

raw heatmap

vector glyph

NEW DIFFICULTY

=>LUT

CAN WE DO BETTER?Spatial

frequencyDensity of coverage Transparency Colour

important?

Heart Low High No Yes

Heatmap Low Low Variable No

Vector High Low Variable No

Glyphs High Low No Yes

CONCLUSION

• Layered visualisations largely an unsolved problem

• Do the benefits for the application outweigh the challenges?

• A layered visualisation can be `modulated’ to assist user’s visual decomposition of each layer

• How many visual channels can we use before the visualisation becomes useless?