DTWFBINIT Dual-Tree Wavelet Filterbank Initialization Usage: dualwt=dtwfbinit(dualwtdef); Input parameters: dualwtdef : Dual-tree filterbank definition. Output parameters: dualwt : Dual-tree filtarbank structure. dtwfinit() (a call without aguments) creates an empty structure. It has the same fields as the struct. returned from WFBTINIT plus a field to hold nodes from the second tree: .nodes Filterbank nodes of the first tree .dualnodes Filterbank nodes of the second tree .children Indexes of children nodes .parents Indexes of a parent node .forder Frequency ordering of the resultant frequency bands. dtwfinit({dualw,J,flag}) creates a structure representing a dual-tree wavelet filterbank of depth J, using dual-tree wavelet filters specified by dualw. The shape of the tree is controlled by flag. Please see help on DTWFB or DTWFBREAL for description of the parameters. [dualwt,info]=dtwfinit(...) additionally returns info struct which provides some information about the computed window: info.tight True if the overall tree construct a tight frame. info.dw A structure containing basic dual-tree filters as returned from fwtinit(dualwtdef,'wfiltdt_'). Additional optional flags ------------------------- 'freq','nat' Frequency or natural ordering of the resulting coefficient subbands. Default ordering is 'freq'.
Package: ltfat