Module wavelet.compression.visu_shrink_compressor
Compression using Universal Threhold
Expand source code
""" Compression using Universal Threhold """
import numpy as np
from wavelet.compression.compressor import Compressor
from wavelet.util.utility import threshold, mad
class VisuShrinkCompressor:
"""
Compressor class to the threshold by using VISU method
Attributes
----------
__compressor: Compressor
object to call the compress function
__threshold: float
threshold for the signal
References
------
Can be used to reduce noise from a audio signal. Better noise
threshold calculation
"""
def __init__(self):
self.__compressor = Compressor()
self.__threshold = None
def compress(self, coefficients):
"""
Thresholding by generated the threshold value
Parameters
----------
coefficients: array_like
input coefficients, output of the decompose method
Returns
-------
array_like
thresholded coefficients
"""
# calculating the noise threhold only one
if self.__threshold is None:
sigma = mad(coefficients)
self.__threshold = sigma * np.sqrt(2 * np.log(len(coefficients)))
return threshold(coefficients, self.__threshold)
def getCompressionRate(self, data):
"""
Returns the compression rate for the input data. Check the Compression
class for the implementation
Parameters
----------
data: array_like
final data
Returns
-------
int, float
output in percentage
"""
return self.__compressor.calculateCompressionRate(data)
def getThreshold(self):
"""
Returns the calculated threshold for the signal
Returns
-------
float
threshold value
"""
return self.__thresholdClasses
class VisuShrinkCompressor-
Compressor class to the threshold by using VISU method
Attributes
__compressor:Compressor- object to call the compress function
__threshold:float- threshold for the signal
References
Can be used to reduce noise from a audio signal. Better noise threshold calculation
Expand source code
class VisuShrinkCompressor: """ Compressor class to the threshold by using VISU method Attributes ---------- __compressor: Compressor object to call the compress function __threshold: float threshold for the signal References ------ Can be used to reduce noise from a audio signal. Better noise threshold calculation """ def __init__(self): self.__compressor = Compressor() self.__threshold = None def compress(self, coefficients): """ Thresholding by generated the threshold value Parameters ---------- coefficients: array_like input coefficients, output of the decompose method Returns ------- array_like thresholded coefficients """ # calculating the noise threhold only one if self.__threshold is None: sigma = mad(coefficients) self.__threshold = sigma * np.sqrt(2 * np.log(len(coefficients))) return threshold(coefficients, self.__threshold) def getCompressionRate(self, data): """ Returns the compression rate for the input data. Check the Compression class for the implementation Parameters ---------- data: array_like final data Returns ------- int, float output in percentage """ return self.__compressor.calculateCompressionRate(data) def getThreshold(self): """ Returns the calculated threshold for the signal Returns ------- float threshold value """ return self.__thresholdMethods
def compress(self, coefficients)-
Thresholding by generated the threshold value
Parameters
coefficients:array_like- input coefficients, output of the decompose method
Returns
array_like- thresholded coefficients
Expand source code
def compress(self, coefficients): """ Thresholding by generated the threshold value Parameters ---------- coefficients: array_like input coefficients, output of the decompose method Returns ------- array_like thresholded coefficients """ # calculating the noise threhold only one if self.__threshold is None: sigma = mad(coefficients) self.__threshold = sigma * np.sqrt(2 * np.log(len(coefficients))) return threshold(coefficients, self.__threshold) def getCompressionRate(self, data)-
Returns the compression rate for the input data. Check the Compression class for the implementation
Parameters
data:array_like- final data
Returns
int, float- output in percentage
Expand source code
def getCompressionRate(self, data): """ Returns the compression rate for the input data. Check the Compression class for the implementation Parameters ---------- data: array_like final data Returns ------- int, float output in percentage """ return self.__compressor.calculateCompressionRate(data) def getThreshold(self)-
Returns the calculated threshold for the signal
Returns
float- threshold value
Expand source code
def getThreshold(self): """ Returns the calculated threshold for the signal Returns ------- float threshold value """ return self.__threshold