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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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Wavelet transform using dwt3 in MATLAB

I have a project to transform an image using dwt. I successfully done it using function dwt2, and now I try to use function dwt3 by changes some code from the function dwt2 (add more subband: 8 subbands). Unfortunately, an error comes out, which…
symlet
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Discrete wavelet transformation of image using D4 wavelet

I'm trying to write forward wavelet transformation using D4 wavelet. Input data is color .bmp image with 24bit/pixel. Wavelet coefficients that I took: h0 = 0.48296 h1 = 0.83652 h2 = 0.22414 h3 = -0.12941 g0 = -0.12941 g1 = -0.22414 g2 = 0.83652 g3…
Tamara
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Multiresolutional wavelet decomposition code

I am not an advanced mathematical, so I understand only the basics of wavelet decomposition. I found JWave, which is a Java implementation of wavelet processing. The author tells me it can by its nature to multidimensional decomposition. The problem…
IamIC
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How to combine arrays of different size into a single cell array?

I am working on DWT in MATLAB, and I want to decompose a 1-D input vector into three levels. The output of the DWT is: w = 1×4 cell array [32×1 double] [16×1 double] [8×1 double] [8×1 double] I have processed each coefficient…
Mohd Yahya
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steganography using DWT in python

I've been doing research on image steganography using DWT. here's my problem: i'm running a code in python and i already got the subbands coefficients of the cover image. but i don't know how to embed the secret image into the cover. A paper says…
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