Visual Attention

1
Visual Attention

• More information in visual field than we can
  process at a given moment
• Solutions
• Shifts of Visual Attention related to eye
  movements
• Some targets pop-out

2
Visual Search

• Feature Integration Theory (Ann Treisman)
• Parallel pre-attentive stage
• Parallel feature detection modules (e.g.
  intensity, color, orientation)
• Feature maps for each module
• Feature maps combinations ? Salience Map

3
Attention Control

• Two Mechanisms
• Bottom-up
• Biases the observer towards selecting stimuli
  based on their saliency
• Importance of unexpected
• Feature maps calculated based on differences to
  neighbors (human eye)
• Top-down
• directs the spotlight of attention under
  cognitive, volitional control
• Importance of desired
• Use of prior information (knowledge)

4
Integration of Motion

• Motion is of fundamental importance in biological
  vision systems
• Contributes to visual attention as confirmed by
  Watanabe et al.
• Weighted summation of the feature maps
• Attending only the moving objects.

5
Integration of Prior Knowledge (top-down)

• Draw attention to regions with specific
  characteristics (e.g. human faces)
• Generate a feature map based on skin activation
• Link it with the rest of the maps

6
Computational Model (Itti Koch)
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Itti Koch map
Equally Weighted maps
Motion Skin biased
May attend only the moving objects!