In contrast to low-level vision, which recovers information from the sensors, mid-level vision concerns how this information gets organized into what we experience as objects and surfaces. ("Mid-level vision" is nearly coextensive with what is called "perceptual organization.")
Contemporary research of mid-level vision draws upon the gestalt tradition in perception, which emerged in Austria in the late 19th century and came of age in Germany in the early 20th century. Following the demise of German science in the 1930s, the gestalt school virtually dissipated (but with some notable exceptions*). For several decades the literature on perceptual organization remained descriptive and amathematical, in the spirit of psychology of the early 20th century. Only recently this started to change. One of the new approaches was introduced by Michael Kubovy of the University of Virginia, who uses tools of mathematical psychology and modern methods of data modeling to discover the lawful structure of perceptual organization.
I joined Kubovy research group in 1997, when I came to the United States from Israel to study perceptual organization. In our joint work we sought to formulate mathematically tractable principles of perceptual organization concerning different perceptual dimensions:
For a recent
review of our approach see .
Here are some details about this work. A complete list of publications is available here.
 Gepshtein, S. & Kubovy, M. (under review). The lawful perception of visual motion. [The manuscript is available on request. A short description of this work is available in the abstract and in the Power Point Slides of a talk given to the European Conference on Visual Perception, Paris, 2003.]
 Gepshtein, S. & Kubovy, M. (in press). Stability and change in perception: Spatial organization in temporal context. Experimental Brain Research. [Preprint]
 Kubovy, M. & Gepshtein, S. (2000). Higher curvature is preferred in the completion of visual contours. Investigative Ophthalmology and Vision Science 41 (4): 2322, B568. [Poster]
 Kubovy, M. & Gepshtein, S.(2003). Perceptual grouping in space and in space-time: An exercise in phenomenological psychophysics. In Behrmann, M., Kimchi, R. & Olson, C. R. (Eds.), Perceptual Organization in Vision: Behavioral and Neural Perspectives. Mahwah, NJ: Lawrence Erlbaum. pp. 45-85. [Preprint]
 Kubovy, M. & Gepshtein, S. (2000). Gestalt: from Phenomena to Laws. In: Perceptual Organization for Artificial Vision Systems. (Eds. Boyer, K. L. & Sarkar, S.) Kluwer Academic Publishers, Boston. p. 41-71. [Reprint]
article by Ken Nakayama provides some further details about mid-level
vision. (You need to subscribe to CogNet to view the linked page.)
[*] Cited above and highly recommended: Ash, M. G. (1995). Gestalt Psychology in German Culture, 1890-1967: Holism and the Quest for Objectivity, Cambridge University Press.