The matrix product of a square set of data 
and a matrix of basis vectors consisting
of Walsh functions. By taking advantage of the
nested structure of the natural ordering of the Walsh
functions, it is possible to speed the transform up from 
to 
steps, resulting in the so-called fast
Walsh transform (Wolfram 2002, p. 1073).
Walsh transforms are widely used for signal and image processing, and can also be
used for image compression (Wolfram 2002, p. 1073).
Walsh Transform
See also
Fast Walsh Transform, Walsh FunctionExplore with Wolfram|Alpha
References
Wolfram, S. A New Kind of Science. Champaign, IL: Wolfram Media, pp. 573 and 1072-1073, 2002.Referenced on Wolfram|Alpha
Walsh TransformCite this as:
Weisstein, Eric W. "Walsh Transform." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/WalshTransform.html