Преобразуйте подъем схемы к квадруплету фильтров
[LoD,HiD,LoR,HiR] = ls2filt(LS)
[LoD,HiD,LoR,HiR] = ls2filt(LS)
возвращает четыре фильтра LoD
, HiD
, LoR
и HiR
, сопоставленный с поднимающейся схемой LS
.
% Start from the db2 wavelet and get the % corresponding lifting scheme. LS = liftwave('db2') LS = 'd' [ -1.7321] [ 0] 'p' [1x2 double] [ 1] 'd' [ 1] [-1] [1.9319] [ 0.5176] [] % Visualize the obtained lifting scheme. displs(LS); LS = {... 'd' [ -1.73205081] [0] 'p' [ -0.06698730 0.43301270] [1] 'd' [ 1.00000000] [-1] [ 1.93185165] [ 0.51763809] [] }; % Get the filters from the lifting scheme. [LoD,HiD,LoR,HiR] = ls2filt(LS) LoD = -0.1294 0.2241 0.8365 0.4830 HiD = -0.4830 0.8365 -0.2241 -0.1294 LoR = 0.4830 0.8365 0.2241 -0.1294 HiR = -0.1294 -0.2241 0.8365 -0.4830 % Get the db2 filters using wfilters. % You can check the equality. [LoDref,HiDref,LoRref,HiRref] = wfilters('db2') LoDref = -0.1294 0.2241 0.8365 0.4830 HiDref = -0.4830 0.8365 -0.2241 -0.1294 LoRref = 0.4830 0.8365 0.2241 -0.1294 HiRref = -0.1294 -0.2241 0.8365 -0.4830