نتایج جستجو برای: frequency domain using fast fourier transform and discrete wavelet transform in data mining stage

تعداد نتایج: 22304961  

2014
Mrugesh Prajapati

In the past few years many new techniques and concepts based on data hiding have been introduced for image authentication and copy right protection. With a lot of information available on various search engines, to protect the ownership of information is a crucial area of research. Digital watermarking is a popular technique that is used for copyright protection and authentication. Digital wate...

Journal: :IEEE transactions on image processing : a publication of the IEEE Signal Processing Society 2000
Michel A. Westenberg Jos B. T. M. Roerdink

We describe a wavelet based X-ray rendering method in the frequency domain with a smaller time complexity than wavelet splatting. Standard Fourier volume rendering is summarized and interpolation and accuracy issues are briefly discussed. We review the implementation of the fast wavelet transform in the frequency domain. The wavelet X-ray transform is derived, and the corresponding Fourier-wave...

Journal: :Journal of Object Technology 2010
Douglas Lyon

This paper is part 6 in a series of papers about the Discrete Fourier Transform (DFT) and the Inverse Discrete Fourier Transform (IDFT). The focus of this paper is on correlation. The correlation is performed in the time domain (slow correlation) and in the frequency domain using a Short-Time Fourier Transform (STFT). When the Fourier transform is an FFT, the correlation is said to be a " fast ...

2007
Laurent Condat Brigitte Forster-Heinlein Dimitri Van De Ville

We present multiresolution spaces of complex rotation-covariant functions, deployed on the 2-D hexagonal lattice. The designed wavelets, which are complex-valued, provide an important phase information for image analysis, which is missing in the discrete wavelet transform with real wavelets. Moreover, the hexagonal lattice allows to build wavelets having a more isotropic magnitude than on the C...

2009
Gerlind Plonka Daniela Roşca

In this paper we consider the Easy Path Wavelet Transform (EPWT) on spherical triangulations. The EPWT has been introduced in [7] in order to obtain sparse image representations. It is a locally adaptive transform that works along pathways through the array of function values and exploits the local correlations of the data in a simple appropriate manner. In our approach the usual one-dimensiona...

2012
Maan M. Shaker

The electroencephalograph (EEG) signal is one of the most widely signal used in the bioinformatics field due to its rich information about human tasks. In this work EEG waves classification is achieved using the Discrete Wavelet Transform DWT with Fast Fourier Transform (FFT) by adopting the normalized EEG data. The DWT is used as a classifier of the EEG wave’s frequencies, while FFT is impleme...

2009
Gaurav Gupta Himanshu Aggarwal

Abstract—In digital watermarking, a watermark is embedded into a cover text in such a way that the resulting watermarked signal is robust to certain distortion caused by either standard data processing in a friendly environment or malicious attacks in an unfriendly environment. This paper presents a digital image watermarking based on two dimensional discrete cosines transform (DCT2), two dimen...

2014
N. Manikanda Devarajan

The orthogonal frequency division multiplexing is used in wireless communication due to high data rate. OFDM are robustness against multi-path fading, frequency selective fading, and narrow band interference. Wavelet analysis has strong advantages over fourier transform and also allows time-frequency domain operation with flexibility. Wavelet is applied in various fields of wireless communicati...

2014
Richika Mahajan B. V. Kranthi

An Improved Image Steganography Technique Using Discrete Wavelet Transform Richika Mahajan, B.V. Kranthi Electronics and Communication Engineering Lovely Professional University Jalandhar, Punjab, India _________________________________________________________________________________________ Abstract: This paper proposes a new method for hiding a data in frequency domain. In this a spatial doma...

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