It is well known that magnetic resonance magnitude image data obey a Rician distribution. Unlike additive Gaussian noise, Rician "noise" is signal-dependent, and separating signal from noise is a difficult task. Rician noise is especially problematic in low signal-to-noise ratio (SNR) regimes where it not only causes random fluctuations, but also introduces a signal-dependent bias to the data t...

Recent studies suggest that physiological noise, which determines the SNR of the fMRI time course at commonly used spatial resolutions, is largely spatially coherent. It is theoretically shown that the ratio of such a spatially coherent physiological to thermal noise determines the optimum voxel volume for maximizing BOLD CNR, relatively independent of the size of activation.

Recently, a novel resource-efficient technique for the reporting channel transmissions in cooperative spectrum sensing was proposed. In this technique, secondary users are allowed to simultaneously send their local decisions to the fusion center, saving time and frequency resources. Expressions for the probabilities of detection and false alarm for the unitary-gain AWGN reporting channels were ...

This article focuses on techniques for acoustic noise reduction, signal filters and source reconstruction. For noise reduction, bandpass filters and cross correlations are found to be efficient and fast ways to improve the signal to noise ratio and identify a possible neutrino-induced acoustic signal. The reconstruction of the position of an acoustic point source in the sea is performed by usin...

The VisuShrink is one of the important image denoising methods. It however does not provide good quality of image due to removing too many coefficients especially using soft-thresholding technique. This paper proposes a new image denoising scheme using wavelet transformation. In this paper, we modify the coefficients using soft-thresholding method to enhance the visual quality of noisy image. T...

conclusion safire reconstruction provided better coronary image quality and displayed the number, morphology, and surrounding lumen of calcium plaques more accurately than traditional fbp reconstruction, with safire3 achieving the best results. results the subjective ratings of image quality using safire1–safire5 reconstructions were significantly higher than those using fbp, with safire3 achie...

Traditional Spread Transform Dither Modulation (ST-DM) is based on the fixed quantization step size, which does not exploit the features of the video contents. Spatio-temporal masking function represents the visual threshold under which human eyes are usually not sensitive. In this paper, we adopts not only the spatial contrast sensitivity function (CSF), the luminance masking function, the con...

As an active remote sensing instrument, lidar provides a high spatial resolution vertical profile of aerosol optical properties. But the effective range and data reliability are often limited by various noises. Performing a proper denoising method will improve the quality of the signals obtained. The denoising method based on ensemble empirical mode decomposition (EEMD) is introduced, but the d...

A detector for the case of a radar target with known Doppler and unknown complex amplitude in complex Gaussian noise with unknown parameters has been derived. The detector assumes that the noise is an Auto-Regressive (AR) process with Gaussian autocorrelation function which is a suitable model for ground clutter in most scenarios involving airborne radars. The detector estimates the unknown...

We demonstrate a new simultaneous normalized detection technique for fluorescence detection of ultracold atoms in a superposition of ground-state hyperfine levels. Using this technique we observe atom shot-noise limited detection signal-to-noise ratios in excess of 7800:1 per shot and 14400:1 in 1 s.