ABSTRACT
At the end of the 1970s mathematical morphology, which had been initially designed as a set theory, went through a wave of extensions toward numerical functions. If the concept is deep, it deserves to apply to other function lattices. In imagery, the two most important ones are multivalued images, obtained from a series of sensors, with color images in particular and motion image sequences. The search for gray-tone operators that are compatible under anamorphosis occurred in connection with the operators based on function thresholds. Beyond gray-tone functions, image processing deals more and more with multi- spectral pictures and with motion pictures. The two upper and lower scalar functions thus generated often carry enough information to serve as markers for gradient and extrema. In image processing gradients are used as contrast descriptors and extrema as dome or blob markers, that is, they are led astray from their initial roles in calculus of variations.
