Figure

1
Figure Form Perception
2
Contrast Effects

• It is contours that segregate objects in most
  forms of visual art.
• We see line easily because our system is designed
  to see them
• The mach bands to the right demonstrate contrast
  effects due to lateral inhibition of visual
  receptors.

3
Spatial frequency

• High Low spatial frequency lines are easily
  perceived by the human visual system.
• Line contour perception is so important that in
  the absence of these types of stimuli (a
  condition known as a ganzfield) you may
  experience some ver disturbing visual perceptions
  or even hallucinations

4
Contrast Effects
Does the gray circle appear to be darker on the
right? This is an example of lateral inhibition
of visual receptors in the retina, thalamus,
primary visual cortex
5
Lightness/Brightness Constancy
The greater the contrast, the brighter the grey
square appears
6
Artists Using Contrast Effects
Brigit Riley, Crest, C. 1964
7
Artists Using Contrast Effects
E. Hopper, Automat, C. 1927
8
Contours Contrast Used to Define Figures
Francis Bacon, Three Studies for a Crucifixion,
1962.
9
Contours, Color, and changes in size, used to
define depth
Jasper Johns, Three Flags, C. 1958
10
Art Defined by Contours
Diego Rivera, The Agitator, C. 1926
11
Helen Frankenthaler, Canal, 1963
12

• Color used as an effective tool for contrast

Edward Munch, The Scream
13
Contrast Effects
Pierre Bonnard, Nude in the Bath, C. 1935, Paris
14

• Complex visual art
• Appreciation of this piece is again dependent on
  the analysis of contours

Pablo Picasso, The Bird Cage, C. 1923, New York