Spectral Impulse Noise Model for Spectral Image Processing

Author(s):  
Hilda Deborah ◽  
Noël Richard ◽  
Jon Yngve Hardeberg
2015 ◽  
Vol 14 (02) ◽  
pp. 1550017
Author(s):  
Pichid Kittisuwan

The application of image processing in industry has shown remarkable success over the last decade, for example, in security and telecommunication systems. The denoising of natural image corrupted by Gaussian noise is a classical problem in image processing. So, image denoising is an indispensable step during image processing. This paper is concerned with dual-tree complex wavelet-based image denoising using Bayesian techniques. One of the cruxes of the Bayesian image denoising algorithms is to estimate the statistical parameter of the image. Here, we employ maximum a posteriori (MAP) estimation to calculate local observed variance with generalized Gamma density prior for local observed variance and Laplacian or Gaussian distribution for noisy wavelet coefficients. Evidently, our selection of prior distribution is motivated by efficient and flexible properties of generalized Gamma density. The experimental results show that the proposed method yields good denoising results.


2013 ◽  
Vol 8-9 ◽  
pp. 611-618
Author(s):  
Florin Toadere ◽  
Radu Arsinte

The paper contains an analysis and simulation of passive pixel based sensors. The passive pixel CMOS image acquisition sensor (PPS) is the key part of a visible image capture systems. The PPS is a complex circuit composed by an optical part and an electrical part, both analog and digital. The goal of this paper is to simulate the functionality of the photodetection process that happens in the PPS sensor. The photodetector is responsible with the conversion from photons to electrical charges and then into current. In the optical part, the sensor is analyzed by a spectral image processing algorithm which uses as input data: the lenses array transmittance, the red, green and blue filters and the quantum efficiency of the PPS. In the electrical part of simulation, the program is computing the signal to noise ratio of the sensor taking into account the photon shot, white and fixed pattern noises. Our basic analysis is based on camera equation to which we add the noises.


Author(s):  
Eduard Kourennyi ◽  
◽  
Alexander Bulgakov ◽  
Arkady Kolomytsev ◽  
◽  
...  

The problems of evaluating the EMC for capacitor units (CU) in power supply systems are considered. The admissible value of the current non-sinusoidal component for the CU was found, it corresponds to the actual standards. The dynamic model of the «supply line – CU» circuit has been substantiated. An equivalent circuit is given. A non-sinusoidal signal is considered as the sum of a sinusoidal and non-sinusoidal component. As a non-sinusoidal component, a voltage pulse noise model with oppositely polar periodic rectangular pulses and pauses was used. Two approaches to determine the useful signal are considered. A physically substantiated interpretation of the concept of non-sinusoidal voltage is proposed for impulse noise. Expressions are given to determine the current noise of the CU. An example of the practical calculation of voltage and current distortion is given. The graphs of the voltage impulse noise and the resulting current noise are shown. An algorithm has been developed to evaluate the effectiveness of means for reducing impulse noise.


1985 ◽  
Vol 24 (04) ◽  
pp. 164-168 ◽  
Author(s):  
P. Mitraszewski ◽  
P. Penczek ◽  
W. Grochulski

SummaryStatistical and deterministic properties of median filters are briefly discussed and their inherent advantages as a prospective tool in scintigraphic data processing are pointed out. The ability of median filters of suppressing impulse noise while the edge-like features of an image are preserved, is demonstrated on phantom data. The residual high-frequency noise remaining after median filtering can be subsequently reduced by standard smoothing procedures. A simple algorithm, made up of the superposition of a median and an averaging filter, is presented and shown to be a promising candidate in the quest for fast and easy-to-implement processing routine.


2018 ◽  
Vol 7 (4) ◽  
pp. 2309
Author(s):  
Baby Victoria.L ◽  
Sathappan S

Noise removal from the color images is the most significant and challenging task in image processing. Among different conventional filter methods, a robust Annihilating filter-based Low-rank Hankel matrix (r-ALOHA) approach was proposed as an impulse noise removal algorithm that uses the sparse and low-rank decomposition of a Hankel structured matrix to decompose the sparse impulse noise components from an original image. However, in this algorithm, the patch image was considered as it was sparse in the Fourier domain only. It requires an analysis of noise removal performance by considering the other transform domains. Hence in this article, the r-ALOHA can be extended into other transform domains such as log and exponential. In the log and exponential domain, the logarithmic and exponential functions are used for modeling the multiplicative noise model. But, this model is used only for positive outcomes. Therefore, wavelet transform domain is applied to the noise model that localizes an image pixel in both frequency and time domain simultaneously. Moreover, it separates the most vital information in a given image. Thus, it is feasible for obtaining a better approximation of the considered function using few coefficients. Finally, the experimental results show the performance effectiveness of the proposed algorithm.  


2015 ◽  
Vol 8 (3) ◽  
pp. 291-303 ◽  
Author(s):  
V. Elamaran ◽  
Har Narayan Upadhyay ◽  
K. Narasimhan ◽  
J. Jezebel Priestley

2020 ◽  
Vol 28 (26) ◽  
pp. 39998
Author(s):  
Fumino Matsui ◽  
Fumiaki Watanabe ◽  
Tomoya Nakamura ◽  
Masahiro Yamaguchi

This paper discusses about various methods involved in detection of avian pox in the birds using images. Digital images are corrupted while sending and receiving the images because of noisy sensors which degrade the quality of image. Pre-processing becomes an initial and crucial step in image processing to remove the noise and maintain fine details and texture of the image. Pre-processed images can be used for further work. Mean, Median, Weiner, Mean Maximum, Mean Minimum filters are used and performance tests are made using Signal Noise Ratio. Based on the performance test, removal of impulse noise is well done by Median filter and produces the best result when compared to other filters. K-Means clustering and SVM are used for identification of the disease.


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