| filterbanks {dualtrees} | R Documentation |
filterbanks for the dtcwt
Description
Some of the filters implemented in the python package dtcwt.
Usage
qshift_b
qshift_b_bp
near_sym_b
near_sym_b_bp
Format
A list of high- and low-pass filters for analysis and synthesis
Details
The near-sym filterbanks are biorthogonal wavelets used for the first level, they have 13 and 19 taps. The qshift filterbanks, each with 14 taps, are suitable for all higher levels of the dtcwt. The a- and b-filters form an approximate Hilbert-pair. The naming convention follows the python-package:
| h: | analysis |
| g: | synthesis |
| 0: | low-pass |
| 1: | high-pass |
| a,b: | shifted filters |
The b_bp-versions of the filterbanks contain a second high-pass for the diagonal directions, denoted by 2. They allow for better directional selectivity but prohibit perfect reconstruction.
Source
'dtcwt' python package (https://github.com/rjw57/dtcwt)
References
Selesnick, I.W., R.G. Baraniuk, and N.C. Kingsbury (2005) <doi:10.1109/MSP.2005.1550194>
Kingsbury, N. (2006) <https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=7071567&isnumber=7065146>