Award-winning monograph of the Ferran Sunyer i Balaguer Prize 2004.
This book studies regularity properties of Mumford-Shah minimizers. The
Mumford-Shah functional was introduced in the 1980s as a tool for
automatic image segmentation, but its study gave rise to many
interesting questions of analysis and geometric measure theory. The main
object under scrutiny is a free boundary K where the minimizer may have
jumps. The book presents an extensive description of the known
regularity properties of the singular sets K, and the techniques to get
them. Some time is spent on the C^1 regularity theorem (with an
essentially unpublished proof in dimension 2), but a good part of the
book is devoted to applications of A. Bonnet's monotonicity and blow-up
techniques. In particular, global minimizers in the plane are studied in
full detail.
The book is largely self-contained and should be accessible to graduate
students in analysis.The core of the book is composed of regularity
results that were proved in the last ten years and which are presented
in a more detailed and unified way.