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Questions tagged [dwt]

DWT stands for Discrete Wavelet Transform. This transformation is commonly used in signal processing. Its main advantage over Fourier transform is its ability to preserve temporal information.

DWT stands for Discrete Wavelet Transform. This transformation is commonly used in signal processing.
Wavelets are considered as more advanced tool than Fourier transform for signal processing. DWT's main advantage is its ability to preserve temporal information of the signal while introducing frequency properties. This advantage is achieved due to the use of compact basis functions - the wavelets. The compact basis functions integrates spectral (frequency) information over compact domain thus preserving temporal information.

There are many types of DWT differes by their construction of their basis function. Very useful DWTs are Haar wavelets and Gabor wavelets.

For more information see wikipedia.

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Discrete Wavelet Transform and frequency boundaries

I'm working with time series and i wonder how to find the frequency subbounds corresponding to the different levels created with Discrete wavelet transform? Thanks
Gwénolé
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Implement document Scanner in web application for TWAIN enabled scanner

I have a web appplication, i want to enable document scanning in that. I already tried working with the dynamosoft dwt, it is working but it is asking for installing some proxy application everytime we want to use it on a different machine to access…
Rishabh singh
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How can we use a basic Discrete Wavelet Transform(DWT) in a CNN layer?

How can we use a basic Discrete Wavelet Transform(DWT) in a CNN layer? If possible can anyone please give a code snippet preferably in python Tensorflow. I want to use this for a image processing task using deep learning and implement DWT as a…
Santosh kumar panda
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DWT feature Extraction

I am working on ECG signals for human identification.i want to extract features from ecg signal using discrete wavelet transform. how I can extract feature from ecg signal. can anyone help me for extracting features?
Muhammad Sheharyar Asif
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How to get matrix 1D from Wavelet DWT using Opencv?

I've tried to use haar wavelet method but the result matrix is not in 1D matrix. How to get 1D matrix from haar wavelet? Here's my code: Import cv2 From pwt import wavedec imgcv1 = cv2.split(resize)[0] cv2.boxFilter(imgcv1, 0, (7,7), imgcv1,…
Novadi Lintang
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how to make a rolling wavelet across array with axis =1 using pywavelets

Im trying to create a rolling wavelet across a array where the row is the rolling window and i want to threshold it by using the max of the window row, but i cant seem to get the code to work: There seems to be a problem with the rolling…
tone
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How to add configurations in Dynamsoft Webtwain

I am trying to implement Dynamsoft Web Twain in my Angular project. There is no config.js file in my node modules. Only dynamsoft.webtwain.min.js and dynamsoft.webtwain.min.mjs is available. So how to add or change the configurations of the…
C J
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Need help in converting MATLAB code to python

I've been trying to implement the MATLAB code of Prof.Selesnick's DWT implementation in Python for learning purposes. function [lo, hi] = afb(x, af) % [lo, hi] = afb(x, af) % % Analysis filter bank % x -- N-point vector (N even); the resolution…
Nice Guy
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i not get dynamsoft ResourcesPath

Dynamsoft.DWT.ResourcesPath = "dwt-resources" Packege.json "scripts": { "dev": "ncp node_modules/dwt/dist static/dwt-resources && nuxt", "build": "nuxt build", "start": "nuxt start", "generate": "nuxt generate && ncp node_modules/dwt/dist…
sorasak menphurk
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Embedding Text in Image DWT coefficients using Python

I'm trying to embed text data into the coefficients of DWT of an image/video frame to perform steganography. I have used PyWavelets to extract coefficients. However, I'm struggling to understand how to manipulate the coefficients of DWT to embed the…
Lulu Bu.
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Decompose and recompose an image using dwt and dct

My idea is to decompose an image using dwt2 first and then apply dct2 to coefficients_approximation, apply a watermark to the result and then recompose the image. final_image = idwt2( idct2 ( dct2 ( dwt2 (starting_image)))) But whenever I do it i…
bog
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ValueError: Input array has fewer dimensions than the specified axes

I was trying to apply discrete wavelet transform on 2D matrix of size (23x7680) but I get this error ValueError: Input array has fewer dimensions than the specified axes. Any help would be appreciated. code: data=np.random.rand(23,7680) coeffs =…
Edayildiz
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Python equivalent of `wavedec3` from MATLAB

I am trying to implement a discrete wavelet transform (DWT) in 3D, and I have found the MATLAB equivalent, wavedec3. Does anyone know if there is a Python equivalent I can use rather than going ahead and writing my own?
Amir Charkhi
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Matlab problem with DWT

I am trying to get the 4th level DWT of an image using the 10 point daubechies filter. (and naturally inverting it!) host = double(imread('lena512.bmp')); % Load image data nLevel = 4; % Number of…
foobar
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How to reconstruct image using HH,HL,LH and LL band of DWT in Python?

i have find the DWT of an image which code is below import numpy as np import matplotlib.pyplot as plt import cv2 import pywt import pywt.data # Load image original = cv2.imread('/content/drive/My Drive/Colab…
Faheem-Ur-Rehman 2305-FETBSEEF
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