نتایج جستجو برای: noise detection

تعداد نتایج: 736140  

2016
Gophika Thanakumar

Digital images are often corrupted by different noises. These noises can be removed by designing an efficient filter. Based upon the specified operation the pixels are classified. Absolute Difference Based Progressive Switching Median Filter (ADBPSMF) outperforms all other filter for the removal of impulse noise from corrupted images. This filter performs two basic operations for efficient nois...

Bahareh Shalchian Hamid Soltanian-Zadeh Hossein Rajabi,

Introduction: An efficient method of tomographic imaging in nuclear medicine is positron emission tomography (PET). Compared to SPECT, PET has the advantages of higher levels of sensitivity, spatial resolution and more accurate quantification. However, high noise levels in the image limit its diagnostic utility. Noise removal in nuclear medicine is traditionally based on Fourier decomposition o...

2015
Renuka Gujral

In Digital image processing; many researches have been done on image denoising so far. Nowadays, the noise detection from an image is the most challenging task. Though, the various algorithms introduced for the detection of noise type from a noisy image, but these algorithms work only for detection of single type of noise. To overcome the limitation of the previous built algorithms, we investig...

Journal: :NeuroImage 2010
Jörg Polzehl Henning U. Voss Karsten Tabelow

Functional Magnetic Resonance Imaging inherently involves noisy measurements and a severe multiple test problem. Smoothing is usually used to reduce the effective number of multiple comparisons and to locally integrate the signal and hence increase the signal-to-noise ratio. Here, we provide a new structural adaptive segmentation algorithm (AS) that naturally combines the signal detection with ...

Introduction: The position estimation in gamma detection system will have constant misplacements which can be corrected in the calibration procedure. In the pixelated crystal uniformly irradiation of detector will produce irregular shape due to position estimation errors. This image is called flood field image and is used to calibrate the position estimation. In this work we pr...

The application of anomaly detection has been given a special place among the different   processings of hyperspectral images. Nowadays, many of the methods only use background information to detect between anomaly pixels and background. Due to noise and the presence of anomaly pixels in the background, the assumption of the specific statistical distribution of the background, as well as the co...

Journal: :The Journal of the Acoustical Society of America 1973

2016
Alex Gurvich Rachel Mandelbaum

The robust estimation of the tiny distortions (shears) of galaxy shapes caused by weak gravitational lensing in the presence of much larger shape distortions due to the point-spread function (PSF) has been widely investigated. One major problem is that most galaxy shape measurement methods are subject to bias due to pixel noise in the images (“noise bias”). Noise bias is usually characterized u...

2011
Zi Yie Mark A Zielke Christopher B Burgner Kimberly L Turner

We experimentally investigate the performance of a nonlinear parametrically driven mass sensor in the presence of detection noise. Mass detection is achieved by measuring the amount of methanol vapor adsorption on the sensor. To demonstrate the advantage of parametric sensing in counteracting the influence of detection noise, we operate the sensor in both the parametric and harmonic resonance m...

Journal: :iranian journal of medical physics 0
bahareh shalchian ph.d. student, medical physics dept., faculty of medical sciences, tarbiat modares university, tehran, iran hossein rajabi associate professor, medical physics dept., faculty of medical sciences, tarbiat modares university, tehran, iran hamid soltanian-zadeh professor, control and intelligent processing center of excellence, electrical and computer engineering dept., university of tehran, tehran, iran

introduction: an efficient method of tomographic imaging in nuclear medicine is positron emission tomography (pet). compared to spect, pet has the advantages of higher levels of sensitivity, spatial resolution and more accurate quantification. however, high noise levels in the image limit its diagnostic utility. noise removal in nuclear medicine is traditionally based on fourier decomposition o...

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