: The idea of summing pairs of so-called semi-wavelets has been found to be very useful for constructing piecewise linear wavelets over refinements of arbitrary triangulations. In this paper we demonstrate the versatility of the semi-wavelet approach by using it to construct bases for the piecewise linear wavelet spaces induced by uniform refinements of four-directional box-spline grids. AMS subject classification: Primary: 41A15, 41A63, Secondary: 65D07 Key words: Waveles, prewavelets, piecewise linear splines, triangulations, local support.
Michael S. Floater, Ewald G. Quak