Active Vision: Directing Visual Attention
R. S. Pieters · 2008
Active vision is the research topic where the vision process is dynamic; i.e. movement of a camera is controlled purposively. The image processing is applied to a sequence of images where a mechanism decides which feature or object should be followed. Attentive vision is an element of active vision where the outcome of an attention selection mechanism differentiates between locations to be attended. When combined, a vision system can direct attention in two ways; top-down and bottom-up tracking. Top-down tracking consists in estimating the position and characteristics of an object of interest, given its position and characteristics in the previous frame. Therefore, particle filters and Kalman filters represent this top-down technique for tracking. The bottom-up approach consists simply in segmenting the object of interest in each frame or Region of Interest and match them over time. This top-down/bottom-up method can also be identified in detecting visual attention. Regard-ing the bottom-up approach, no prior knowledge for salience is used to direct attention selection. However, top-down mechanisms could be employed to direct attention to certain objects which