segmentation

Definition

Segmentation labels every pixel (or voxel, or token) rather than the input as a whole, producing a mask that traces the outline of each region of interest. It is the standard formulation wherever exact boundaries carry meaning — tumor volumes, drivable road surface, land cover — and is strictly harder than detection, which only needs a bounding box. Semantic segmentation groups pixels by class; instance segmentation separates individual objects of the same class.

In the textbook

• Detection and Segmentation