# -*- coding: utf-8 -*-
# Copyright (c) 2015 Holger Nahrstaedt
# See COPYING for license details.
"""
Helper function for wavelet denoising
"""
from __future__ import division, print_function, absolute_import
import numpy as np
import sys as sys
from ._pyyawt import *
__all__ = ['orthfilt', 'biorfilt', 'dbwavf', 'coifwavf', 'symwavf', 'legdwavf', 'biorwavf', 'rbiorwavf', 'wfilters', 'wmaxlev', 'dwtmode']
[docs]def orthfilt(w):
"""
orthfilt is an utility function for obtaining analysis and synthesis filter set of given orthogonal wavelets including haar, daubechies, coiflets and symlets
Parameters
----------
w: array_like
scaling filter
Returns
-------
Lo_D: array_like
lowpass analysis filter
Hi_D: array_like
highpass analysis filter
Lo_R: array_like
lowpass synthesis filter
Hi_R: array_like
highpass synthesis filter
Examples
--------
F = dbwavf("db2")
[lo_d,hi_d,lo_r,hi_r]=orthfilt(F)
"""
m1 = 1
n1 = w.shape[0]
Lo_D = np.zeros(n1,dtype=np.float64)
Hi_D = np.zeros(n1,dtype=np.float64)
Lo_R = np.zeros(n1,dtype=np.float64)
Hi_R = np.zeros(n1,dtype=np.float64)
_orthfilt(w,Lo_D,Hi_D,Lo_R,Hi_R)
return Lo_D,Hi_D,Lo_R,Hi_R
[docs]def biorfilt(df,rf):
"""
biorfilt is an utility function for obtaining analysis and synthesis filter set of given bi-orthogonal spline wavelets. DF and RF should be output of biorfilt result with the same length.
Parameters
----------
df: array_like
analysis scaling filter
rf: array_like
synthesis scaling filter
Returns
-------
Lo_D: array_like
lowpass analysis filter
Hi_D: array_like
highpass analysis filter
Lo_R: array_like
lowpass synthesis filter
Hi_R: array_like
highpass synthesis filter
Examples
--------
RF,DF = biorwavf('bior3.3')
[lo_d,hi_d,lo_r,hi_r]=biorfilt(DF,RF)
"""
m1 = 1
n1 = df.shape[0]
Lo_D = np.zeros(n1,dtype=np.float64)
Hi_D = np.zeros(n1,dtype=np.float64)
Lo_R = np.zeros(n1,dtype=np.float64)
Hi_R = np.zeros(n1,dtype=np.float64)
_biorfilt(df,rf,Lo_D,Hi_D,Lo_R,Hi_R)
return Lo_D,Hi_D,Lo_R,Hi_R
[docs]def dbwavf(wname):
"""
dbwavf is an utility function for obtaining scaling filter of daubechies wavelet.
Parameters
----------
wname: str
wavelet name, 'db1' to 'db36'
Returns
-------
F: array_like
scaling filter
Examples
--------
F = dbwavf("db2")
"""
ret = _wavelet_parser(wname.encode())
if (ret[0] != PYYAWT_DAUBECHIES):
raise Exception("Wrong wavelet name!")
lowPass = np.zeros(_wfilters_length(wname.encode()),dtype=np.float64)
_dbwavf(wname.encode(),b'Lo_R',lowPass)
return lowPass
[docs]def coifwavf(wname):
"""
coifwavf is an utility function for obtaining scaling filter of coiflets wavelet.
Parameters
----------
wname: str
wavelet name, 'coif1' to 'coif5'
Returns
-------
F: array_like
scaling filter
Examples
--------
F = coifwavf('coif3')
"""
ret = _wavelet_parser(wname.encode())
if (ret[0] != PYYAWT_COIFLETS):
raise Exception("Wrong wavelet name!")
lowPass = np.zeros(_wfilters_length(wname.encode()),dtype=np.float64)
_coifwavf(wname.encode(),b'Lo_R',lowPass)
return lowPass
[docs]def symwavf(wname):
"""
symwavf is an utility function for obtaining scaling filter of symlets wavelet.
Parameters
----------
wname: str
wavelet name, 'sym2' to 'sym20'
Returns
-------
F: array_like
scaling filter
Examples
--------
F = symwavf('sym7')
"""
ret = _wavelet_parser(wname.encode())
if (ret[0] != PYYAWT_SYMLETS):
raise Exception("Wrong wavelet name!")
lowPass = np.zeros(_wfilters_length(wname.encode()),dtype=np.float64)
_symwavf(wname.encode(),b'Lo_R',lowPass)
return lowPass
[docs]def legdwavf(wname):
"""
legdwavf is an utility function for obtaining scaling filter of legendre wavelet.
Parameters
----------
wname: str
wavelet name, 'legd1' to 'legd9'
Returns
-------
F: array_like
scaling filter
Examples
--------
F = legdwavf('sym7')
"""
ret = _wavelet_parser(wname.encode())
if (ret[0] != PYYAWT_LEGENDRE):
raise Exception("Wrong wavelet name!")
lowPass = np.zeros(_wfilters_length(wname.encode()),dtype=np.float64)
_legdwavf(wname.encode(),b'Lo_R',lowPass)
return lowPass
[docs]def biorwavf(wname):
"""
biorwavf is an utility function for obtaining twin scaling filters of bi-orthogonal spline wavelet including bior1.1, bior1.3, bior1.5, bior2.2, bior2.4, bior2.6, bior2.8, bior3.1, bior3.3, bior3.5, bior3.7, bior3.9, bior4.4, bior5.5 and bior6.8. Although the twin filters have different length, zeros has been fed to keep two filters the same length.
Parameters
----------
wname: str
wavelet name, 'bior1.1' to 'bior6.8'
Returns
-------
RF: array_like
synthesis scaling filter
DF: array_like
analysis scaling filter
Examples
--------
RF,DF = biorwavf('bior3.3');
"""
ret = _wavelet_parser(wname.encode())
if (ret[0] != PYYAWT_SPLINE_BIORTH):
raise Exception("Wrong wavelet name!")
filterLength = _wfilters_length(wname.encode())
RF = np.zeros(filterLength, dtype=np.float64)
DF = np.zeros(filterLength, dtype=np.float64)
_biorwavf(wname.encode(),b'Lo_R',False,RF)
_biorwavf(wname.encode(),b'Lo_D',True,DF)
return RF,DF
[docs]def rbiorwavf(wname):
"""
rbiorwavf is an utility function for obtaining twin scaling filters of bi-orthogonal spline wavelet including bior1.1, bior1.3, bior1.5, bior2.2, bior2.4, bior2.6, bior2.8, bior3.1, bior3.3, bior3.5, bior3.7, bior3.9, bior4.4, bior5.5 and bior6.8. Although the twin filters have different length, zeros has been fed to keep two filters the same length. rbiorwavf is reversing the results of biorwavf.
Parameters
----------
wname: str
wavelet name, 'rbior1.1' to 'rbior6.8'
Returns
-------
RF: array_like
synthesis scaling filter
DF: array_like
analysis scaling filter
Examples
--------
[RF,DF]=rbiorwavf('rbior3.3')
"""
ret = _wavelet_parser(wname.encode())
if (ret[0] != PYYAWT_SPLINE_RBIORTH):
raise Exception("Wrong wavelet name!")
RF = np.zeros(_wfilters_length(wname.encode()),dtype=np.float64)
DF = np.zeros(_wfilters_length(wname.encode()),dtype=np.float64)
_rbiorwavf(wname.encode(),b'Lo_R',False,RF)
_rbiorwavf(wname.encode(),b'Lo_D',True,DF)
return RF,DF
[docs]def wfilters(wname,filterType=None):
"""wfilters is an utility function for obtaining analysis and synthesis filter set.
Calling Sequence
----------------
[Lo_D,Hi_D,Lo_R,Hi_R]=wfilters(wname)
[Lo_D,Hi_D]=wfilters(wname,'d')
[Lo_R,Hi_R]=wfilters(wname,'r')
[Lo_D,Lo_R]=wfilters(wname,'l')
[Hi_D,Hi_R]=wfilters(wname,'h')
Parameters
----------
wname: str
wavelet name, wavelet name, haar( "haar"), daubechies ("db1" to "db20"), coiflets ("coif1" to "coif5"), symlets ("sym2" to "sym20"), legendre ("leg1" to "leg9"), bathlets("bath4.0" to "bath4.15" and "bath6.0" to "bath6.15"), dmey ("dmey"), beyklin ("beylkin"), vaidyanathan ("vaidyanathan"), biorthogonal B-spline wavelets ("bior1.1" to "bior6.8"), "rbior1.1" to "rbior6.8"
Returns
-------
Lo_D: array_like
lowpass analysis filter
Hi_D: array_like
highpass analysis filter
Lo_R: array_like
lowpass synthesis filter
Hi_R: array_like
highpass synthesis filter
Examples
--------
[lo_d,hi_d,lo_r,hi_r]=wfilters('db2')
"""
ret_family, ret_member = _wavelet_parser(wname.encode())
if (np.any(ret_family == np.array([PYYAWT_FARRAS, PYYAWT_KINGSBURYQ, PYYAWT_NOT_DEFINED]))):
raise Exception("Wrong wavelet name!")
filterLength = _wfilters_length(wname.encode())
Lo_D = np.zeros(filterLength,dtype=np.float64)
Hi_D = np.zeros(filterLength,dtype=np.float64)
Lo_R = np.zeros(filterLength,dtype=np.float64)
Hi_R = np.zeros(filterLength,dtype=np.float64)
if (ret_family == PYYAWT_DAUBECHIES):
_dbwavf(wname.encode(),b'Lo_D',Lo_D)
_dbwavf(wname.encode(),b'Hi_D',Hi_D)
_dbwavf(wname.encode(),b'Lo_R',Lo_R)
_dbwavf(wname.encode(),b'Hi_R',Hi_R)
elif (ret_family == PYYAWT_COIFLETS):
_coifwavf(wname.encode(),b'Lo_D',Lo_D)
_coifwavf(wname.encode(),b'Hi_D',Hi_D)
_coifwavf(wname.encode(),b'Lo_R',Lo_R)
_coifwavf(wname.encode(),b'Hi_R',Hi_R)
elif (ret_family == PYYAWT_SYMLETS):
_symwavf(wname.encode(),b'Lo_D',Lo_D)
_symwavf(wname.encode(),b'Hi_D',Hi_D)
_symwavf(wname.encode(),b'Lo_R',Lo_R)
_symwavf(wname.encode(),b'Hi_R',Hi_R)
elif (ret_family == PYYAWT_SPLINE_BIORTH):
_biorwavf(wname.encode(),b'Lo_D',False,Lo_D)
_biorwavf(wname.encode(),b'Hi_D',False,Hi_D)
_biorwavf(wname.encode(),b'Lo_R',False,Lo_R)
_biorwavf(wname.encode(),b'Hi_R',False,Hi_R)
elif (ret_family == PYYAWT_BEYLKIN):
_beylkinwavf(wname.encode(),b'Lo_D',Lo_D)
_beylkinwavf(wname.encode(),b'Hi_D',Hi_D)
_beylkinwavf(wname.encode(),b'Lo_R',Lo_R)
_beylkinwavf(wname.encode(),b'Hi_R',Hi_R)
elif (ret_family == PYYAWT_VAIDYANATHAN):
_vaidyanathanwavf(wname.encode(),b'Lo_D',Lo_D)
_vaidyanathanwavf(wname.encode(),b'Hi_D',Hi_D)
_vaidyanathanwavf(wname.encode(),b'Lo_R',Lo_R)
_vaidyanathanwavf(wname.encode(),b'Hi_R',Hi_R)
elif (ret_family == PYYAWT_DMEY):
_dmeywavf(wname.encode(),b'Lo_D',Lo_D)
_dmeywavf(wname.encode(),b'Hi_D',Hi_D)
_dmeywavf(wname.encode(),b'Lo_R',Lo_R)
_dmeywavf(wname.encode(),b'Hi_R',Hi_R)
elif (ret_family == PYYAWT_BATHLETS):
_bathletswavf(wname.encode(),b'Lo_D',Lo_D)
_bathletswavf(wname.encode(),b'Hi_D',Hi_D)
_bathletswavf(wname.encode(),b'Lo_R',Lo_R)
_bathletswavf(wname.encode(),b'Hi_R',Hi_R)
elif (ret_family == PYYAWT_LEGENDRE):
_legendrewavf(wname.encode(),b'Lo_D',Lo_D)
_legendrewavf(wname.encode(),b'Hi_D',Hi_D)
_legendrewavf(wname.encode(),b'Lo_R',Lo_R)
_legendrewavf(wname.encode(),b'Hi_R',Hi_R)
elif (ret_family == PYYAWT_SPLINE_RBIORTH):
_rbiorwavf(wname.encode(),b'Lo_D',False,Lo_D)
_rbiorwavf(wname.encode(),b'Hi_D',False,Hi_D)
_rbiorwavf(wname.encode(),b'Lo_R',False,Lo_R)
_rbiorwavf(wname.encode(),b'Hi_R',False,Hi_R)
elif (ret_family == PYYAWT_HAAR):
_haarwavf(wname.encode(),b'Lo_D',Lo_D)
_haarwavf(wname.encode(),b'Hi_D',Hi_D)
_haarwavf(wname.encode(),b'Lo_R',Lo_R)
_haarwavf(wname.encode(),b'Hi_R',Hi_R)
elif (ret_family == PYYAWT_FARRAS):
_farraswavf(wname.encode(),b'Lo_D',Lo_D)
_farraswavf(wname.encode(),b'Hi_D',Hi_D)
_farraswavf(wname.encode(),b'Lo_R',Lo_R)
_farraswavf(wname.encode(),b'Hi_R',Hi_R)
elif (ret_family == PYYAWT_KINGSBURYQ):
_kingsburyqwavf(wname.encode(),b'Lo_D',Lo_D)
_kingsburyqwavf(wname.encode(),b'Hi_D',Hi_D)
_kingsburyqwavf(wname.encode(),b'Lo_R',Lo_R)
_kingsburyqwavf(wname.encode(),b'Hi_R',Hi_R)
# _wfilters(wname.encode(),Lo_D,Hi_D,Lo_R,Hi_R)
if (filterType is None):
flow = 1
return Lo_D, Hi_D, Lo_R, Hi_R
elif (filterType == 'd'):
flow = 2
return Lo_D, Hi_D
elif (filterType == 'r'):
flow = 3
return Lo_R, Hi_R
elif (filterType == 'l'):
flow = 4
return Lo_D, Lo_R
elif (filterType == 'h'):
flow = 5
return Hi_D, Hi_R
else:
raise Exception("Wrong input!")
[docs]def wmaxlev(signalLength,wname):
"""
wmaxlev is the maximum decompostion level calculation utility.
Parameters
----------
signalLength: int
signal length
wname: str
wavelet name, wavelet name, haar( "haar"), daubechies ("db1" to "db20"), coiflets ("coif1" to "coif5"), symlets ("sym2" to "sym20"), legendre ("leg1" to "leg9"), bathlets("bath4.0" to "bath4.15" and "bath6.0" to "bath6.15"), dmey ("dmey"), beyklin ("beylkin"), vaidyanathan ("vaidyanathan"), biorthogonal B-spline wavelets ("bior1.1" to "bior6.8"), "rbior1.1" to "rbior6.8"
Returns
-------
L: int
decomposition level
Examples
--------
L=wmaxlev(100,'db5')
"""
if (np.size(signalLength) == 1):
filterLength = _wfilters_length(wname.encode())
stride, val = _wave_len_validate(signalLength,filterLength)
if (val == 0):
raise Exception("Unrecognized Input Pattern or parameter not valid for the algorithm! Please refer to help pages!\n")
return stride
elif (np.size(signalLength) == 2):
filterLength = _wfilters_length(wname.encode())
stride1, val1 = _wave_len_validate(signalLength[0],filterLength)
if (val1 == 0):
raise Exception("The wavelet you select is not appropriate for that row size of the matrix!\n")
stride2, val2 = _wave_len_validate(signalLength[1],filterLength)
if (val2 == 0):
raise Exception("The wavelet you select is not appropriate for that column size of the matrix!\n")
return np.min([stride1, stride2])
else:
return 0
[docs]def dwtmode(mode=None, nodisp=None):
"""
dwtmode is to display or change extension mode.
Parameters
----------
mode: str
'symh'('sym'), 'symw', 'asymh', 'asymw', 'zpd', 'zpd', 'per', 'ppd'.
nodisp: str
None or 'nodisp'
Returns
-------
mode: str
extension mode
Examples
--------
dwtmode()
dwtmode('status')
mode=dwtmode('status','nodisp')
dwtmode(mode)
"""
mode_strings = np.array(['zpd','symh', 'symw', 'asymh', 'asymw', 'sp0', 'sp1', 'ppd', 'per'])
modes = np.array([PYYAWT_ZPD, PYYAWT_SYMH, PYYAWT_SYMW, PYYAWT_ASYMH, PYYAWT_ASYMW, PYYAWT_SP0,
PYYAWT_SP1, PYYAWT_PPD, PYYAWT_PER])
if (mode is None or mode == "status" and nodisp is None):
dwtmode = _getdwtMode()
if (dwtmode == PYYAWT_ZPD):
print("** DWT Extension Mode: Zero Padding **\n")
elif (dwtmode == PYYAWT_SYMH):
print("** DWT Extension Mode: Half Symmetrization **\n")
elif (dwtmode == PYYAWT_SYMW):
print("** DWT Extension Mode: Whole Symmetrization **\n")
elif (dwtmode == PYYAWT_ASYMH):
print("** DWT Extension Mode: Half Asymmetrization **\n")
elif (dwtmode == PYYAWT_ASYMW):
print("** DWT Extension Mode: Whole Asymmetrization **\n")
elif (dwtmode == PYYAWT_SP0):
print("** DWT Extension Mode: order 0 smooth padding **\n")
elif (dwtmode == PYYAWT_SP1):
print("** DWT Extension Mode: order 1 smooth padding **\n")
elif (dwtmode == PYYAWT_PPD):
print("** DWT Extension Mode: Periodic Padding**\n")
elif (dwtmode == PYYAWT_PER):
print("** DWT Extension Mode: Periodization **\n")
elif (np.any(mode == modes)):
errCode = _dwtWrite(mode_strings[np.where(mode == modes)[0]].encode())
if (errCode > 0):
raise Exception("DWT Extension Mode error")
elif (np.any(mode == mode_strings)):
errCode = _dwtWrite(mode.encode())
if (errCode > 0):
raise Exception("DWT Extension Mode error")
elif (mode == "status" and nodisp == "nodisp"):
dwtmode = _getdwtMode()
modestr = ""
if (dwtmode == PYYAWT_ZPD):
modestr = 'zpd'
elif (dwtmode == PYYAWT_SYMH):
modestr = 'symh'
elif (dwtmode == PYYAWT_SYMW):
modestr = 'symw'
elif (dwtmode == PYYAWT_ASYMH):
modestr = 'asymh'
elif (dwtmode == PYYAWT_ASYMW):
modestr = 'asymw'
elif (dwtmode == PYYAWT_SP0):
modestr = 'sp0'
elif (dwtmode == PYYAWT_SP1):
modestr = 'sp1'
elif (dwtmode == PYYAWT_PPD):
modestr = 'ppd'
elif (dwtmode == PYYAWT_PER):
modestr = 'per'
return modestr
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