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3D face shape adaptation across changes in viewpoint, lighting and reflectance

Conference Paper


Abstract


  • Four experiments are reported using face adaptation to look at encoding of three-dimensional (3D) face shape across changes in viewpoint, lighting direction and surface reflectance. Categorization as Japanese or Caucasian was used as a task. A face-space was defined in terms of a principal components analysis (PCA) of 3D feature point positions with Linear Discriminant Analysis (LDA) used to define a direction within that space that best captured ethnicity. Adaptation was measure as a change in the point of subjective equality (PSE) along that dimension. Experiment 1 showed a shift in the point of subjective equality in the direction of the adapting population that transferred between views (15ð and 45ð). Experiment 2 used exaggerated adapting faces and showed increased adaptation that transferred across a change in modelled surface reflectance as well as view (from 30ð to 0ð and 60ð). Experiment 3 showed that adaptation was not affected by having the same or different lighting at adaptation and test. Experiment 4 tested adaptation from 0ð to 90ð and found a fall-off with increasing angle of rotation. The results are interpreted as evidence for the encoding of 3D face shape independent of image properties at least over a limited range of viewpoint

UOW Authors


  •   Hill, Harold
  •   Watson, Tamara (external author)
  •   Vignal, Guillaume (external author)

Publication Date


  • 2007

Citation


  • Hill, H. C., Watson, T. & Vignal, G. (2007). 3D face shape adaptation across changes in viewpoint, lighting and reflectance. EPC 2007: 34th Australasian Experimental Psychology Conference (pp. 55-55). Canberra: Australian National University.

Ro Metadata Url


  • http://ro.uow.edu.au/hbspapers/981

Start Page


  • 55

End Page


  • 55

Abstract


  • Four experiments are reported using face adaptation to look at encoding of three-dimensional (3D) face shape across changes in viewpoint, lighting direction and surface reflectance. Categorization as Japanese or Caucasian was used as a task. A face-space was defined in terms of a principal components analysis (PCA) of 3D feature point positions with Linear Discriminant Analysis (LDA) used to define a direction within that space that best captured ethnicity. Adaptation was measure as a change in the point of subjective equality (PSE) along that dimension. Experiment 1 showed a shift in the point of subjective equality in the direction of the adapting population that transferred between views (15ð and 45ð). Experiment 2 used exaggerated adapting faces and showed increased adaptation that transferred across a change in modelled surface reflectance as well as view (from 30ð to 0ð and 60ð). Experiment 3 showed that adaptation was not affected by having the same or different lighting at adaptation and test. Experiment 4 tested adaptation from 0ð to 90ð and found a fall-off with increasing angle of rotation. The results are interpreted as evidence for the encoding of 3D face shape independent of image properties at least over a limited range of viewpoint

UOW Authors


  •   Hill, Harold
  •   Watson, Tamara (external author)
  •   Vignal, Guillaume (external author)

Publication Date


  • 2007

Citation


  • Hill, H. C., Watson, T. & Vignal, G. (2007). 3D face shape adaptation across changes in viewpoint, lighting and reflectance. EPC 2007: 34th Australasian Experimental Psychology Conference (pp. 55-55). Canberra: Australian National University.

Ro Metadata Url


  • http://ro.uow.edu.au/hbspapers/981

Start Page


  • 55

End Page


  • 55