4.2. Algorithms and PDEs. Many mathematical approaches have been investigated
for applications in artificial vision (e.g., fractals and self-similarity, wavelets,
pattern theory, stochastic point process, random graph theory; see [42]). In particular,
methods based on partial differential equations (PDEs) have been extremely
popular in the past few years [20, 35]. Here we briefly outline the major concepts
involved in using PDEs for image processing.