scholarly journals Rapid visual categorization of natural scene contexts with equalized amplitude spectrum and increasing phase noise

10.1167/9.1.2 ◽  
2009 ◽  
Vol 9 (1) ◽  
pp. 2-2 ◽  
Author(s):  
O. R. Joubert ◽  
G. A. Rousselet ◽  
M. Fabre-Thorpe ◽  
D. Fize
Keyword(s):  
Phase Noise ◽  
Amplitude Spectrum ◽  
Natural Scene ◽  
Visual Categorization

Different spatial frequency bands selectively signal for natural image statistics in the early visual system

2012 ◽  
Vol 108 (8) ◽  
pp. 2160-2172 ◽  
Author(s):  
Bruce C. Hansen ◽  
Aaron P. Johnson ◽  
Dave Ellemberg
Keyword(s):  
Spatial Frequency ◽  
Broad Band ◽  
Amplitude Spectrum ◽  
Structural Complexity ◽  
Luminance Contrast ◽  
Natural Image ◽  
Natural Image Statistics ◽  
Natural Scene ◽  
Image Statistics ◽  
Neural Processes

Early visual evoked potentials (VEPs) measured in humans have recently been observed to be modulated by the image statistics of natural scene imagery. Specifically, the early VEP is dominated by a strong positivity when participants view minimally complex natural scene imagery, with the magnitude of that component being modulated by luminance contrast differences across spatial frequency (i.e., the slope of the amplitude spectrum). For scenes high in structural complexity, the early VEP is dominated by a prominent negativity that exhibits little dependency on luminance contrast. However, since natural scene imagery is broad band in terms of spatial frequency, it is not known whether the above-mentioned modulation results from a complex interaction within or between the early neural processes tuned to different bands of spatial frequency. Here, we sought to address this question by measuring early VEPs (specifically, the C1, P1, and N1 components) while human participants viewed natural scene imagery that was filtered to contain specific bands of spatial frequency information. The results show that the C1 component is largely unmodulated by the luminance statistics of natural scene imagery (being only measurable when such stimuli were made to contain high spatial frequencies). The P1 and N1, on the other hand, were observed to exhibit strong spatial frequency-dependent modulation to the luminance statistics of natural scene imagery. The results therefore suggest that the dependency of early VEPs on natural image statistics results from an interaction between the early neural processes tuned to different bands of spatial frequency.

Understanding Jitter and Phase Noise

2018 ◽  
Author(s):  
Nicola Da Dalt ◽  
Ali Sheikholeslami
Keyword(s):  
Phase Noise

Estimation of PSF Using Logarithmic Amplitude Spectrum and Restoration of Blurred Image

2012 ◽  
Vol 132 (2) ◽  
pp. 284-290
Author(s):  
Yuka Nagashima ◽  
Shigeru Omatu ◽  
Michifumi Yoshioka
Keyword(s):  
Amplitude Spectrum ◽  
Blurred Image

Extension of the LTV Phase Noise Model of Electrical Oscillators for the Output Harmonics

2012 ◽  
Vol E95.C (12) ◽  
pp. 1846-1856 ◽  
Author(s):  
Seyed Amir HASHEMI ◽  
Hassan GHAFOORIFARD ◽  
Abdolali ABDIPOUR
Keyword(s):  
Phase Noise ◽  
Noise Model ◽  
Electrical Oscillators

Phase Noise Measurement of Optical Heterodyning Two-Tone Signal Generated by Two Free-Running Lasers

2013 ◽  
Vol E96.C (2) ◽  
pp. 241-244
Author(s):  
Ryuta YAMANAKA ◽  
Taka FUJITA ◽  
Hideyuki SOTOBAYASHI ◽  
Atsushi KANNO ◽  
Tetsuya KAWANISHI
Keyword(s):  
Phase Noise ◽  
Noise Measurement ◽  
Tone Signal ◽  
Free Running
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