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For the issue of image denoising, in order to avoid the traditional multi-scale sparse representation methods, which used blocks of different sizes as a base function to represent image, the non-separable wavelets were taken. Their advantages included revealing the multi-scale structure, depicting the texture structure under different scales, and separating different directions and different types...
The instantaneous frequency is an important feature of GPR image and signal. However, the traditional method either cannot realize the instantaneous frequency extraction in real sense or can only apply for narrow-band signal. The HHT method can extract intrinsic model function (IMF), and then combines Hilbert transfer to get the instantaneous frequency which can represent the time-varying frequency...
In this paper, we present a novel method to image denoising using non-separable wavelet based SURE-LET approach. Unlike conventional separable wavelet filter banks that limit the ability in capturing directional information, non-separable wavelet filter banks contain the basis elements oriented at a variety of directions which are able to capture different detail information. Using SURE-LET makes...
Images often contain noise due to the capturing devices, environment and even human errors. For the image further processing, compression, fractal and so on, the image denoising is necessary. Wavelet analysis plays a very important role in the image denoising. In this paper, we improve the wavelet thresholding method by using multi-scale thresholds and a new thresholding function. Also, in case of...
Face recognition has been studied extensively recently. The main difficulty faced by the current face recognition techniques stems from large variations in facial expression, pose and illumination. This paper presents an effective method for face recognition using nonseparable wavelet domain block-based PCA(BPCA) method. Our investigations demonstrate that the constructed nonseparable wavelet can...
Writer identification recently has been considerably studied due to its various applications in forensic and commercial sections. Because offline, text-independent writer identification has limited requirements in writing sample collection, it has wider applications and meanwhile more difficult to handle. By considering handwriting images as visually distinctive textures, we propose a new method for...
Fingerprint enhancement is necessary for low quality images. In this paper, we develop a new method for fingerprint enhancement based on non-separable filter banks. We first decompose the fingerprint image using the non-separable filter banks, which can decompose the fingerprint image efficiently and obtain wavelet coefficients, then modifies the coefficients by applying the adaptive approach to reduce...
With the use of distributed renewable energy resources in the building low-voltage distribution network, voltage fluctuations are of rising concerns. This paper aims to make use of a computational algorithm to identify voltage fluctuations by the use wavelet-based transform. The continuous wavelet transform (CWT) using the complex Morlet wavelet (CMW) is adopted to detect the voltage fluctuations...
This paper presents a computational algorithm for estimating the amplitudes of nonstationary power system harmonics waveforms. The algorithm is based on Complex Continuous Wavelet Transform (CCWT) by using a modified Complex Morlet Wavelet (CMW). Experimental work has been done to demonstrate the effectiveness of the proposed waveform reconstruction algorithm.
The detection method of pests in stored grain is always investigated. The method of based on image recognition is often discussed.The wavelet transform is the localization analysis of time and frequency, and it can multi-scale refine the signal by calculating of flex and transition. This paper presents a method of using the wavelet transform to detect the image of pests in stored grain edge based...
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