# Questions tagged [dwt]

DWT denotes discrete wavelet transforms, instances of continuous wavelet transforms that admit a discrete sampling.

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### Why no Daubechies wavelet from Continuous Wavelet Transform?

thank you for considering this question. Do you know any reason why Daubechies wavelet can't be used for Continuous Wavelet Transfrom, but only for Discrete Wavelet Transform ? Matlab toolbox and ...
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### Avoiding latency distortion at high denoise levels with DWT

I am denoising biological signals using the DWT, and for UI reasons would prefer the smoother waveform afforded by denoise level 5. However, higher denoise levels seem to distort the latency of ...
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### discrete wavelet transform matrix for vectorized image

Yesterday I asked about how to extract 2D DFT matrix for a vectorized image. Today my question is how can I extract 2D DWT matrix for a vectorized image. Fourier transform have this property that ...
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1 vote
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### Difference between "Discrete Wavelet Transform" and "Discrete Wavelet Decomposition"

I have a rough overview on Discrete Wavelet Transform (DWT). However, I am confused about Discrete Wavelet Decomposition and did not find a good reference yet which explains this well. What is it ...
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### Extracting feature from audio track using DWT

Our teacher gave us an assignment: Write a program to transform an audio track to time - frequency domain, and create a vector include at least 4 features extracted from transformed output signal. I ...
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### Other time-frequency-plane tiling than STFT, DWT, ConstantQ-Transform: multiresolution STFT?

It is known that a) the STFT gives a rectangular tiling of the time-frequency plane b) the Wavelet transform gives a non-linear tiling (better frequency resolution for low-frequencies, and better ...
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### Dimensional reduction from DWT with threshold

I have been trying to find out how can the discrete wavelet transform (DWT) be possible to reduce dimension of data. Then I saw the question which is seemingly related to my work: Feature extraction/...
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1 vote
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### What are the best suitable type of image moments (Hu, Zernike etc.) that can be applied on an Image after DCT/DWT?

I want to perform a block by block comparison by using overlapping blocks and their respective image moments. Can anybody suggest for type of image moment suited for blocks of DCT/DWT of that image. ...
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### Which of DFT, DCT and DWT transforms is more robust to noise and geometric transformations in image processing [closed]

I am currently studying about image watermarking and I have been testing these 3 domains to embed the watermark at. My question is, how do these domains hold up to noise addition or geometric ...
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### Programming the IDWT for image processing

I want to program the 2D inverse discrete wavelet transform (only 1 level) in the case of image processing. In the matlab website there's this diagram: now, I want to program the IDWT with haar ...
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### Real-time wavelet decomposition and reconstruction for ECG feature extraction

I need to locate R-peaks in an ECG signal. I'm using wavelets to extract QRS complexes: First, I decompose the signal using a maximal overlap discrete wavelet transform with the Symlet 4 wavelet. This ...
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### why double desity DWT use two HPF?

The double-density DWT is an improvement upon the critically sampled DWT with important additional properties: It employs one scaling function and two distinct wavelets, which are designed to be ...
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### DWT versus band-pass filter

Which technique gives better result in extracting a band from a signal, let's say the alpha band (8-13 Hz): using a band-pass-filter or a DWT (Discrete Wavelet Transformation)? P.S.: I am working in ...
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### Implementing the DWT

I have been given the task to implement the 5/3 CDF transform for image compression. Given that the impulse response for the low and high pass are: $h_1 = [-0.5, 1 ,-0.5]$ (High Pass) \$h_2 = [-0....
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### Can anyone help me with good reference books for Discrete Wavelet Transform (DWT)

I am working on EEG signal. To analyze the signal I need to use DWT. Therefore I need good reference books. If the book contains MATLAB implementation of DWT that will be more helpful.
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