The de-noising is a challenging task in the field of signal and image processing. Any natural image corrupted by gussian noise can be de-noised using wavelet method. Wavelet-based image denoising is an important technique in the area of image noise reduction. Wavelets have their natural ability to represent images in a very sparse form which is the foundation of wavelet-based denoising through ...

In the fluorescence detection system, noise will affect the sensitivity of the system. The method using Stationary Wavelet Transform to de-noise fluorescence signals based on adaptive wavelet entropy is studied. The de-noising effects of dbN families are compared, and then the db7 wavelet is chosen as the optimal wavelet. The noised fluorescence signal is decomposed at 5 levels via Discrete Wav...

The rope-less elevator driven by Permanent Magnet Linear Synchronous Motor (PMLSM) is a new technology for high-rise buildings. In the practical operation, PMLSM inevitably encounters various kinds of turbulences which directly affect the rope-less elevator’s operation. The braking system is important for rope-less elevator safe and steady operation. Usually, the ordinary inspections are not ab...

Due to electromagnetic interference in power substations, the partial discharge (PD) signals detected by ultrahigh frequency (UHF) antenna sensors often contain various background noises, which may hamper high voltage apparatus fault diagnosis and localization. This paper proposes a novel de-noising method based on the generalized S-transform and module time-frequency matrix to suppress noise i...

The natural frequency and scanning vibration frequency of C-dynamic scanning system of laser sensors are acquired for film thickness of lithium battery de-noising based on multi-resolution wavelet algorithm. For this reason, fast de-noising based on atomic sequence template library is present. First, under various mode of scanning, best atomic sequence template is built by sparse decomposition....

The wavelet de-noising technique with wavelet based function has been used in this paper for bearing fault detection. The applications of the wavelet de-noising show that the fault pulses in time-domain of the de-noised signals are easily to be detected as a result of removing the covering noise, which is not possible through the time-domain analysis of the original signal. Furthermore, the rec...

Donoho and Johnstone (1992a) proposed a method for reconstructing an unknown function f on [0; 1] from noisy data di = f(ti) + zi, i = 0; : : : ; n 1, ti = i=n, zi iid N(0; 1). The reconstruction f̂ n is de ned in the wavelet domain by translating all the empirical wavelet coe cients of d towards 0 by an amount p 2 log(n) = p n. We prove two results about that estimator. [Smooth]: With high prob...

Solar cell is known as a sustainable and environment friendly source of energy in nature. It converts sunlight directly into electricity with zero emission and also without side-effects on the environment. But, solar cells have optical and mechanical defects which include the type of micro crack, the size of crack, and the noise from electrical or electromechanical interference during the image...

in this paper, an optimal algorithm is presented for de-noising of medical images. the presented algorithm is based on improved version of local pixels grouping and principal component analysis. in local pixels grouping algorithm, blocks matching based on l2 norm method is utilized, which leads to matching performance improvement. to evaluate the performance of our proposed algorithm, peak sign...

This paper presents an approach which addresses both de-noising and contrast enhancement. In a multiscale wavelet analysis framework, we take advantage of both soft thresholding and hard thresholding wavelet shrinkage techniques to reduce noise. In addition, we carry out nonlinear processing to enhance contrast within structures and along boundaries. Feature restoration and enhancement are acco...