continuous and discrete signals. There are many other multi-scale signal processing, image processing and data compression techniques, using wavelets and a variety of other kernels, that do not exploit or require the same requirements as scale space descriptions do; that is, they do not depend on a coarser scale not generating a new extremum that was not present at a finer scale (in 1D) or non-enhancement of local extrema between adjacent scale levels (in any number of dimensions). See also Scale space Pyramid (image processing) Multi-scale approaches Gaussian filter References Image processing Computer vision Gaussian function