[1] Mallat S, Hwang W L. Singularity detection and processing with wavelets[J]. IEEE Trans IT, 1992,38(2): 617-643.
[7] Marr D, Hildreth E. Theory of edge detection[J]. Proceeding of Royal Society of London, 1980, 207:187-217.
[8] Mallat S. Zero-crossings of a wavelet transform[J]. IEEE Trans IT, 1991,37(4): 1019-1033.