The middle level of image processing is mainly concerned with extracting descriptions of the scene from the image descriptions extracted at the low level. The output is usually in some more symbolic form, describing the position and shape of portions of the scene. The analysis usually does not know anything about what objects are in the scene, but does use a lot of knowledge of scene shape and how shape appears in an image. In our coffee mug example, the kinds of descriptions one might expect are 3D position of the edges of the mug, portions of its surface shape, depth relationships between adjacent surface patches, which features are moving and where, etc.
Active or flexible contour models
Grouping Edges: The Formation of Contours
Shape from Shading
Image Segmentation and Representation in Two Dimensions
Surface Description and Segmentation
Binary Image Processing
Stereo Vision
Comments to: Sarah Price at ICBL.
(Last update: 22th April, 1996)