CS781 - Colour for Computer Graphics - Winter 2009

Lecture 5

Surface Reflectance

Generalized Bidirectional Reflectance Distribution Functions

Reflectance varies with

Each of these has both incoming and outgoing dependence

Subjective Effects of Coloured Surfaces

Area effects

Colour perception is very acute for large areas of uniform colour

How to handle it

  1. Carpets, shirts
  2. Paint
  3. Bricks

Surface constancy

Principal Components Analysis of Colour

Where did it come from

Principal Components Analysis

Given a very large sample of data, how can you summarise it?


  1. The usual least squares problems
  2. Sample dependence
  3. There is usually not a well-defined break point

Possible Remedies

  1. We know the dimension

PCA of Coloured Surfaces

PCA of Coloured Light

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