The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
A method operating at an outdoor swimming pool is presented in this paper. In a swimming pool, one key problem we faced is that the SNR (signal to noise ratio) will be lower than general surroundings such as bubbles, shadow, water waves, and lower contrast. In order to eliminate noise and preserve the edge and texture detail in the image that we obtained, we select the wavelet denoising algorithm...
To overcome the shortcomings of hard threshold method and soft threshold method of wavelet threshold based signal denoising, a new threshold function is presented in this paper. This function combines hard threshold function and soft threshold function, which has good mathematical properties and physical significance. It can be used in various cases of denoising by selecting suitable parameters. Simulation...
In order to improve the de-noising effect of wavelet threshold further, after analyzing the shortcomings of the traditional soft and hard threshold de-noising methods, this paper proposes a trade-off of soft and hard threshold method. The typical blocks signal superposed standard Gaussian white noise in the Matlab wavelet toolbox is taken as an example for simulating and testing, to verify the feasibility...
To obtain a high robust of speech recognition for noisy conditions, a new pre-processing stage based on wavelet thresholding algorithm is proposed in this paper. The purpose of using the DWT is to benefit from its localization property in the time and frequency domains. Compromise function is proposed compared with hard and soft thresholding function. A new thresholding value, Neyman-Pearson criterion...
To solve the problem of roll eccentricity signal with the noise in the HAGC system, a new method based on adaptive threshold de-noising algorithm of roll eccentricity signal is proposed. The new method can self-adaptively decide the threshold of wavelet analysis and make the SNR as a function of the parameter of the filter to acquire the optimal threshold parameter by using midpoint method. This method...
The wavelet transform coefficient is processed by using grey relation analysis of the grey theory, and a new wavelet threshold method - GID (grey incidence degree) threshold method based on the wavelet analysis theory is introduced. The test shows that the signal smoothness and similarity of the two signal criteria have been greatly improved by the GID threshold method compared with existing threshold...
Wavelet threshold denoising is a powerful method for suppressing noise in signals and images. However, this method uses a coordinate-wise processing scheme, which ignores the structural properties in the wavelet coefficients. We propose a new denoising method using sparse representation which is a powerful mathematical tool developed only recently. Instead of thresholding wavelet coefficients individually,...
QRS detection is important because R peak is recognized as the most useful fiducial point in ECG segmentation. Despite of lot of research effort, the accuracy and robustness of QRS detection still remain open problems. Here we propose a novel QRS detector, which uses the Discrete Wavelet Transform (DWT) and Cubic Spline Interpolation as preprocessor, together with an improved dynamic weights adjusting...
In this paper, we design an enhanced human-computer speech interface by wavelet transform. By using a new thresholding algorithm and shrink function, we improve the efficiency of the speech interface. This shrink function tries to decrease sharp time-frequency spectrogram discontinuities by attenuating the wavelet coefficients instead of setting them to zero. This attenuation will be done regarding...
The aim of astronomical spectra denoising is to reduce the noise level, while preserving astrophysical information hidden in spectra. Many astronomical spectra denoising approaches exist, in which wavelet thresholding approaches are widely adopted in many literatures. For spectra denoising using wavelet thresholding, the thresholding function greatly influences the quality of the resulting denoised...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.