Coiflet
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Coiflet is a discrete wavelet designed by Ingrid Daubechies to be more symmetrical than the Daubechies wavelet. Whereas Daubechies wavelets have vanishing moments, Coiflet scaling functions have zero moments and their wavelet functions have . They are named in honor of Ronald Coifman, who first requested them.
Coiflet coefficients
Both the scaling function (low-pass filter) and the wavelet function (High-Pass Filter) must be normalised by a factor . Below are the coefficients for the scaling functions for C6-30. The wavelet coefficients are derived by reversing the order of the scaling function coefficients and then reversing the sign of every second one. (ie. C6 wavelet = {−0.022140543057, 0.102859456942, 0.544281086116, −1.205718913884, 0.477859456942, 0.102859456942}) Mathematically, this looks like where k is the coefficient index, B is a wavelet coefficient and C a scaling function coefficient. N is the wavelet index, ie 6 for C6.
k | C6 | C12 | C18 | C24 | C30 |
---|---|---|---|---|---|
0 | −0.102859456942 | 0.023175193479 | −0.005364837341 | 0.001261922093 | −0.000000134600 |
1 | 0.477859456942 | −0.058640275960 | 0.011006253418 | −0.002304449705 | −0.000000236800 |
2 | 1.205718913884 | −0.095279180620 | 0.033167120958 | −0.010389048053 | 0.000002918600 |
3 | 0.544281086116 | 0.546042093070 | −0.093015528958 | 0.022724918488 | 0.000005281600 |
4 | −0.102859456942 | 1.149364787715 | −0.086441527120 | 0.037734470756 | −0.000030144000 |
5 | −0.022140543057 | 0.589734387392 | 0.573006670549 | −0.114928468858 | −0.000058464200 |
6 | −0.108171214184 | 1.122570513741 | −0.079305297034 | 0.000198755200 | |
7 | −0.084052960922 | 0.605967143547 | 0.587334781789 | 0.000427459600 | |
8 | 0.033488820325 | −0.101540281510 | 1.106252905125 | −0.000902454000 | |
9 | 0.007935767225 | −0.116392501524 | 0.614314652395 | −0.002351644400 | |
10 | −0.002578406712 | 0.048868188642 | −0.094225477729 | 0.003441309400 | |
11 | −0.001019010797 | 0.022458481925 | −0.136076254102 | 0.009566002800 | |
12 | −0.012739202022 | 0.055627280306 | −0.012960180000 | ||
13 | −0.003640917832 | 0.035471674876 | −0.027947375800 | ||
14 | 0.001580410202 | −0.021512637034 | 0.046221554000 | ||
15 | 0.000659330348 | −0.008002025773 | 0.058391759000 | ||
16 | −0.000100385550 | 0.005305331892 | −0.149304477801 | ||
17 | −0.000048931468 | 0.001791189058 | −0.087732101600 | ||
18 | −0.000833001142 | 0.619413698002 | |||
19 | −0.000367659537 | 1.095010858804 | |||
20 | 0.000088160707 | 0.596184647002 | |||
21 | 0.000044165714 | −0.073600147200 | |||
22 | −0.000004609884 | −0.129994525601 | |||
23 | −0.000002524350 | 0.039835608600 | |||
24 | 0.033104132800 | ||||
25 | −0.014327563800 | ||||
26 | −0.005882221600 | ||||
27 | 0.003080491400 | ||||
28 | 0.000507122400 | ||||
29 | −0.000299927600 |