Noise Models for Ill-Posed Problems

2015 ◽  
pp. 1-24
Author(s):  
Paul N. Eggermont ◽  
Vincent LaRiccia ◽  
M. Zuhair Nashed
Keyword(s):  
2013 ◽  
pp. 1-24
Author(s):  
Paul N. Eggermont ◽  
Vincent LaRiccia ◽  
M. Zuhair Nashed
Keyword(s):  

2010 ◽  
pp. 739-762
Author(s):  
Paul N. Eggermont ◽  
Vincent LaRiccia ◽  
M. Zuhair Nashed
Keyword(s):  

2015 ◽  
pp. 1633-1658 ◽  
Author(s):  
Paul N. Eggermont ◽  
Vincent LaRiccia ◽  
M. Zuhair Nashed
Keyword(s):  

Author(s):  
B. Roy Frieden

Despite the skill and determination of electro-optical system designers, the images acquired using their best designs often suffer from blur and noise. The aim of an “image enhancer” such as myself is to improve these poor images, usually by digital means, such that they better resemble the true, “optical object,” input to the system. This problem is notoriously “ill-posed,” i.e. any direct approach at inversion of the image data suffers strongly from the presence of even a small amount of noise in the data. In fact, the fluctuations engendered in neighboring output values tend to be strongly negative-correlated, so that the output spatially oscillates up and down, with large amplitude, about the true object. What can be done about this situation? As we shall see, various concepts taken from statistical communication theory have proven to be of real use in attacking this problem. We offer below a brief summary of these concepts.


1997 ◽  
Vol 44 (10) ◽  
pp. 1929-1936 ◽  
Author(s):  
A. BRAMATI, V. JOST, F. MARIN and E. G

1983 ◽  
Vol 45 (5) ◽  
pp. 1237-1245 ◽  
Author(s):  
O. M. Alifanov
Keyword(s):  

Sensors ◽  
2019 ◽  
Vol 19 (24) ◽  
pp. 5459
Author(s):  
Wei Deng ◽  
Eric R. Fossum

This work fits the measured in-pixel source-follower noise in a CMOS Quanta Image Sensor (QIS) prototype chip using physics-based 1/f noise models, rather than the widely-used fitting model for analog designers. This paper discusses the different origins of 1/f noise in QIS devices and includes correlated double sampling (CDS). The modelling results based on the Hooge mobility fluctuation, which uses one adjustable parameter, match the experimental measurements, including the variation in noise from room temperature to –70 °C. This work provides useful information for the implementation of QIS in scientific applications and suggests that even lower read noise is attainable by further cooling and may be applicable to other CMOS analog circuits and CMOS image sensors.


2008 ◽  
Vol 29 (3-4) ◽  
pp. 445-469
Author(s):  
Pham Hoang Quan ◽  
Dang Duc Trong ◽  
Alain Pham Ngoc Dinh
Keyword(s):  

Author(s):  
Radu Boţ ◽  
Guozhi Dong ◽  
Peter Elbau ◽  
Otmar Scherzer

AbstractRecently, there has been a great interest in analysing dynamical flows, where the stationary limit is the minimiser of a convex energy. Particular flows of great interest have been continuous limits of Nesterov’s algorithm and the fast iterative shrinkage-thresholding algorithm, respectively. In this paper, we approach the solutions of linear ill-posed problems by dynamical flows. Because the squared norm of the residual of a linear operator equation is a convex functional, the theoretical results from convex analysis for energy minimising flows are applicable. However, in the restricted situation of this paper they can often be significantly improved. Moreover, since we show that the proposed flows for minimising the norm of the residual of a linear operator equation are optimal regularisation methods and that they provide optimal convergence rates for the regularised solutions, the given rates can be considered the benchmarks for further studies in convex analysis.


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