A procedure is developed to quantify and improve the signal-to-noise ratio (SNR) of Magnetic Resonance images. The image SNR is quanti ed using the correlation function of two independent acquisitions of an image. To test the performance of the quanti cation, SNR measurement data are tted to theoretically expected curves. The proposed correlation technique is also used to improve the SNR by est...

 Edge Detection is an important task for sharpening the boundary of images to detect the region of interest. This paper applies a linear cellular automata rules and a Mamdani Fuzzy inference model for edge detection in both monochromatic and the RGB images. In the uniform cellular automata a transition matrix has been developed for edge detection. The Results have been compared to the ...

A new two-step fuzzy filter that adopts a fuzzy logic approach for the enhancement of images corrupted with impulse noise is presented in this paper. The filtering method (entitled as Fuzzy Random Impulse Noise Reduction method (FRINR)) consists of a fuzzy detection mechanism and a fuzzy filtering method to remove (random-valued) impulse noise from corrupted images. Based on the criteria of pea...

A method for detection of a Direct-Sequence Spread Spectrum (DS-SS) communication hidden in the noise is proposed. Indeed, DS-SS signals are well-known for their low probability of interception: their statistics are similar to the statistics of a noise, and, furthermore, they are usually transmitted below the noise level. The proposed method is based on the uctuations of autocorrelation estima...

Background: Speech perception ability depends on auditory and extra-auditory elements. The signal-to-noise ratio (SNR) is an extra-auditory element that has an effect on the ability to normally follow speech and maintain a conversation. Speech in noise perception difficulty is a common complaint of the elderly. In this study, the importance of SNR magnitude as an extra-auditory effect on speech...

Random or incoherent noise is an important type of seismic noise, which can seriously affect the quality of the data. Therefore, decreasing the level of this category of noises is necessary for increasing the signal-to-noise ratio (SNR) of seismic records. Random noises and other events overlap each other in time domain, which makes it difficult to attenuate them from seismic records. In this r...

  Objective(s): In SPECT, the sinogram contains scatter and lack of attenuated counts that degrade the reconstructed image quality and quantity. Many techniques for attenuation and scatter correction have been proposed. An acceptable method of correction is to incorporate effects into an iterative statistical reconstruction. Here, we propose new Maximum Likelihood Expectation Maximiz...

1. Biomedical Imaging Group, EPFL, CH-1015 Lausanne VD, Switzerland. 2. Escuela Politecnica Superior, Univ. San Pablo-CEU, Campus Urb. Monteprincipe s/n, 28668 Boadilla del Monte, Madrid, Spain. 3. Lab. d'analyse ultrastructurale, Univ. de Lausanne, CH-1015 Lausanne VD, Switzerland. 4. Howard Hughes Medical Institute, Molecular & cell biology Dept. Univ. of California, Berkeley, Ca 94720, USA. ...

A long-term aim of current research into the frequency assignment problem is to identify features that would enable us to classify instances of the problem in terms of certain easily-computed parameters. Although there are good mathematical reasons why this may be impossible in full generality, experimental evidence is emerging which suggests that instances which occur in practice may be amenab...