e/Ridge detection

Information
has gloss	eng: The ridges (or the ridge set) of a smooth function of two variables is a set of curves whose points are, loosely speaking, local maxima in at least one dimension. For a function of N variables, its ridges are a set of curves whose points are local maxima in N-1 dimensions. (A more precise definition is given below). In this respect, the notion of ridge points can be seen as an extension of the concept of a local maximum. Correspondingly, the notion of valleys for a function can be defined by replacing the condition of a local maximum with the condition of a local minimum. The union of ridge sets and valley sets, together with a related set of points called the connector set form a connected set of curves that partition intersect or meet at the critical points of the function. This union of sets together is called the function's relative critical set.
lexicalization	eng: ridge detection
instance of	e/Smooth function