  Gestalt theory has provided perceptual science with a conceptual framework
which has inspired researchers ever since, taking the field of perceptual
organization into the 21st century. This opinion article discusses the
importance of rules of perceptual organization for the testing and design of
visual interface technology. It is argued that major Gestalt principles, such
as the law of good continuation or the principle of Praegnanz (suggested
translation: salience), taken as examples here, are important to our
understanding of visual image processing by a human observer. Perceptual
integration of contrast information across collinear space, and the
organization of objects in the 2D image plane into figure and ground are of a
particular importance here. Visual interfaces for image-guided surgery
illustrate the criticality of these two types of perceptual processes for
reliable decision making and action. It is concluded that Gestalt theory
continues to generate powerful concepts and insights for perceptual science
placed within the context of major technological challenges of today.
