Various image processing applications exploit a model of the human visual system (HVS). One element of HVSmodels describes the masking-effect, which is typically parameterized by psycho-visual experiments that employ superimposed sinusoidal stimuli. Those stimuli are oversimplified with respect to real images and can capture only very elementary maskingeffects. To overcome these limitations a n...

We investigated whether the oriented trails of blur left by fast-moving dots (i.e., "motion streaks") effectively mask grating targets. Using a classic overlay masking paradigm, we varied mask contrast and target orientation to reveal underlying tuning. Fast-moving Gaussian blob arrays elevated thresholds for detection of static gratings, both monoptically and dichoptically. Monoptic masking at...

A new mechanism expanding mycoplasmal surface diversity is described. Exposure of surface epitopes on a constitutively expressed membrane protein (P56) of Mycoplasma hominis was subject to high-frequency phase variation due to phase-variable expression of the P120 antigen and its selective masking of P56 epitopes. Phase-variable masking may confer previously unrealized adaptive capabilities on ...

Frequency and amplitude discrimination thresholds along the kinesthetic to cutaneous continuum were evaluated on the left index fingerpad using a multifinger tactual display. Target stimuli were presented either in isolation (no-masker condition) or in the presence of masking stimuli (one- or two-masker conditions). Six reference target signals in the frequency range 2-300 Hz (two each from low...

Over the years, a variety of array processing techniques have been applied to the problem of enhancing degraded speech to improve automatic speech recognition. In this context, linear beamforming has long been the approach of choice, for reasons including good performance, robustness and analytical simplicity. While various nonlinear techniques – typically based to some extent on the study of a...

Contrast-modulated (CM) gratings, composed of two luminance-modulated sinusoids of similar spatial frequency, mask the detection of test sinusoids at the difference frequency. However, the mechanism underlying masking by CM gratings remains poorly understood. In this paper, we aimed to determine whether the masking of 1 cycle deg(-1) LM test gratings by a 1 cycle deg(-1) beat (formed from a pai...

This paper describes the development of an auditory filterbank to perform the initial frequency analysis in models of human hearing and speech perception. It is based on the gammatone function used by physiologists to summarise 'revcor' measurements of the impulse response of the auditory filter in small mammals. The first section shows that the amplitude characteristic of the gammatone functio...