Dr. Stanley A. Klein Profile

Dr. Stanley A. Klein

Professor at Univ of California Berkeley

SPIE Involvement:

Author

Publications (27)

Proceedings Article | 18 February 2010 Paper

Human brain imaging during controlled and natural viewing

Stanley Klein, Thom Carney, David Kim, Sangita Dandekar, Claudio Privitera

Proceedings Volume 7527, 752707 (2010) https://doi.org/10.1117/12.849104

KEYWORDS: Electroencephalography, Magnetoencephalography, Visualization, Eye, Wavelets, Brain-machine interfaces, Functional magnetic resonance imaging, Magnetic resonance imaging, Skull, Head

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Proceedings Article | 14 February 2008 Paper

The pupil dilation response to visual detection

Claudio Privitera, Laura Renninger, Thom Carney, Stanley Klein, Mario Aguilar

Proceedings Volume 6806, 68060T (2008) https://doi.org/10.1117/12.772844

KEYWORDS: Visualization, Target detection, Eye, Target recognition, Sensors, Temporal resolution, Satellite imaging, Earth observing sensors, Satellites, Error analysis

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Proceedings Article | 14 February 2008 Paper

Combining MRI and VEP imaging to isolate the temporal response of visual cortical areas

Thom Carney, Justin Ales, Stanley Klein

Proceedings Volume 6806, 680608 (2008) https://doi.org/10.1117/12.773383

KEYWORDS: Visualization, Electroencephalography, Magnetoencephalography, Functional magnetic resonance imaging, Electrodes, Visual process modeling, Process control, Magnetic resonance imaging, Signal to noise ratio, Spatial frequencies

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The human brain has well over 30 cortical areas devoted to visual processing. Classical neuro-anatomical as well as fMRI studies have demonstrated that early visual areas have a retinotopic organization whereby adjacent locations in visual space are represented in adjacent areas of cortex within a visual area. At the 2006 Electronic Imaging meeting we presented a method using sprite graphics to obtain high resolution retinotopic visual evoked potential responses using multi-focal m-sequence technology (mfVEP). We have used this method to record mfVEPs from up to 192 non overlapping checkerboard stimulus patches scaled such that each patch activates about 12 mm² of cortex in area V1 and even less in V2. This dense coverage enables us to incorporate cortical folding constraints, given by anatomical MRI and fMRI results from the same subject, to isolate the V1 and V2 temporal responses. Moreover, the method offers a simple means of validating the accuracy of the extracted V1 and V2 time functions by comparing the results between left and right hemispheres that have unique folding patterns and are processed independently. Previous VEP studies have been contradictory as to which area responds first to visual stimuli. This new method accurately separates the signals from the two areas and demonstrates that both respond with essentially the same latency. A new method is introduced which describes better ways to isolate cortical areas using an empirically determined forward model. The method includes a novel steady state mfVEP and complex SVD techniques. In addition, this evolving technology is put to use examining how stimulus attributes differentially impact the response in different cortical areas, in particular how fast nonlinear contrast processing occurs. This question is examined using both state triggered kernel estimation (STKE) and m-sequence "conditioned kernels". The analysis indicates different contrast gain control processes in areas V1 and V2. Finally we show that our m-sequence multi-focal stimuli have advantages for integrating EEG and MEG for improved dipole localization.

Proceedings Article | 9 February 2006 Paper

Advances in multifocal methods for imaging human brain activity

Thom Carney, Justin Ales, Stanley Klein

Proceedings Volume 6057, 605716 (2006) https://doi.org/10.1117/12.674151

KEYWORDS: Visualization, Electrodes, Video, Modulation, Electroencephalography, Brain, Visual cortex, Cortical activation, Neuroimaging, Functional magnetic resonance imaging

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Proceedings Article | 13 June 2002 Paper

Wide-angle cornea-sclera (OCULAR) topography

Stanley Klein, John Corzine, Jacob Corbin, Sheldon Wechsler, Thom Carney

Proceedings Volume 4611, (2002) https://doi.org/10.1117/12.470589

KEYWORDS: Cornea, Eye, Contact lenses, Surgery, Sclera, Cameras, Optical spheres, Standards development, Mirrors, Light scattering

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Proceedings Article | 30 May 2002 Paper

Extending the modelfest image/threshold database into the spatio-temporal domain

Thom Carney, Stanley Klein, Brent Beutter, Anthony Norcia, Chien-Chung Chen, Christopher Tyler, Walter Makous, Andrew Watson, Simon Cropper, Ariella Popple, Ken Robertson, Velitchko Manahilov, Bill Simpson, Klara Wenzel

Proceedings Volume 4662, (2002) https://doi.org/10.1117/12.469510

KEYWORDS: Data modeling, Visual process modeling, Motion models, Performance modeling, Binary data, Video, Databases, Visual system, Visualization, Image compression

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Proceedings Article | 7 June 2001 Paper

Problems with wavefront aberrations applied to refractive surgery: developing standards

Stanley Klein

Proceedings Volume 4245, (2001) https://doi.org/10.1117/12.429289

KEYWORDS: Wavefronts, Surgery, Standards development, Prisms, Cornea, Visualization, Night vision, Databases, Wavefront aberrations, Point spread functions

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Proceedings Article | 7 June 2000 Paper

Evaluation of entire-cornea topography measurement

Fergal Shevlin, Stanley Klein, Robert Mandell, Thom Carney

Proceedings Volume 3908, (2000) https://doi.org/10.1117/12.387538

KEYWORDS: Cornea, Reflection, Reconstruction algorithms, Detection and tracking algorithms, Computer simulations, Manufacturing, Data centers, Calibration, Distortion, Shape analysis

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Proceedings Article | 2 June 2000 Paper

Modelfest: year one results and plans for future years

Thom Carney, Christopher Tyler, Andrew Watson, Walter Makous, Brent Beutter, Chien-Chung Chen, Anthony Norcia, Stanley Klein

Proceedings Volume 3959, (2000) https://doi.org/10.1117/12.387150

KEYWORDS: Data modeling, Visual process modeling, Spatial frequencies, Human vision and color perception, Databases, Video compression, Composites, Visualization, Performance modeling, Image compression

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Proceedings Article | 18 June 1999 Paper

Measuring effects of refractive surgery on corneas using Taylor series polynomials

Jacob Corbin, Stanley Klein, Corina van de Pol

Proceedings Volume 3591, (1999) https://doi.org/10.1117/12.350598

KEYWORDS: Cornea, Monochromatic aberrations, Surgery, Eye, Zernike polynomials, Visualization, Ophthalmology, Contrast sensitivity, Data acquisition, Optical spheres

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Proceedings Article | 18 June 1999 Paper

Wavefront coherence area for predicting visual acuity of post-PRK and post-PARK refractive surgery patients

Daniel Garcia, Corina van de Pol, Brian Barsky, Stanley Klein

Proceedings Volume 3591, (1999) https://doi.org/10.1117/12.350591

KEYWORDS: Cornea, Visualization, Wavefronts, Surgery, Eye, Visual analytics, Geometrical optics, Laser ablation, Refraction, Tolerancing

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Proceedings Article | 19 May 1999 Paper

Development of an image/threshold database for designing and testing human vision models

Thom Carney, Stanley Klein, Christopher Tyler, Amnon Silverstein, Brent Beutter, Dennis Levi, Andrew Watson, Adam Reeves, Anthony Norcia, Chien-Chung Chen, Walter Makous, Miguel Eckstein

Proceedings Volume 3644, (1999) https://doi.org/10.1117/12.348473

KEYWORDS: Visual process modeling, Data modeling, Spatial frequencies, Databases, Visualization, Image quality, Image compression, Human vision and color perception, Performance modeling, Linear filtering

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Proceedings Article | 19 May 1999 Paper

Effects of dynamic quantization noise on video quality

Thom Carney, Yuan-Chi Chang, Stanley Klein, David Messerschmitt

Proceedings Volume 3644, (1999) https://doi.org/10.1117/12.348435

KEYWORDS: Video, Video compression, Quantization, Video coding, Image compression, Algorithm development, Visualization, Image segmentation, Computer programming, Signal processing

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Proceedings Article | 17 July 1998 Paper

Effects of temporal jitter on video quality: assessment using psychophysical and computational modeling methods

Yuan-Chi Chang, Thom Carney, Stanley Klein, David Messerschmitt, Avideh Zakhor

Proceedings Volume 3299, (1998) https://doi.org/10.1117/12.320108

KEYWORDS: Video, Video compression, Video coding, Computer programming, Image segmentation, Image quality, Visualization, Quantization, Human vision and color perception, Computational modeling

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Proceedings Article | 1 June 1998 Paper

CWhatUC: a visual acuity simulator

Daniel Garcia, Brian Barsky, Stanley Klein

Proceedings Volume 3246, (1998) https://doi.org/10.1117/12.309444

KEYWORDS: Cornea, Visualization, Monochromatic aberrations, Eye, Computer simulations, Refraction, Computing systems, Scientific visualization, Optical spheres, 3D modeling

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Proceedings Article | 3 June 1997 Paper

Seven models of masking

Stanley Klein, Thom Carney, Lauren Barghout-Stein, Christopher Tyler

Proceedings Volume 3016, (1997) https://doi.org/10.1117/12.274510

KEYWORDS: Transducers, Visual process modeling, Data modeling, Spatial frequencies, Visualization, Image compression, Visibility, Samarium, Medical imaging, Eye

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Proceedings Article | 3 June 1997 Paper

Partitioning mechanisms of masking: contrast transducer versus divisive inhibition

Lauren Barghout-Stein, Christopher Tyler, Stanley Klein

Proceedings Volume 3016, (1997) https://doi.org/10.1117/12.274550

KEYWORDS: Transducers, Interference (communication), Spatial frequencies, Systems modeling, Visualization, Psychophysics, Signal to noise ratio, Visual system, Target detection, Signal detection

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The properties of spatial vision mechanisms are often explored psychophysically with simultaneous masking paradigms. A variety of hypotheses have been proposed to explain how the mask pattern utilized in these paradigms increases threshold. Numerous studies have investigated the properties of a particular origin of masking hypothesis but few have attempted to compare the properties of masking at several points in the process. Our study isolates masking due to lateral divisive inhibition at a point where mechanism responses are combined, and compares it with masking of the same target due to a nonlinearity either intrinsic to a mechanism or directly operating on the response of a single mechanism. We also measure the slopes of psychometric functions to examine the relationship between uncertainty and mask contrast. Studies of simultaneous masking utilizing a pedestal mask (an identical test and mask pattern) have measured facilitation for low contrast masks. This decrease in threshold from the solo target threshold is commonly referred to as the 'dipper' effect and has been explained as an increase in signal-to- noise ratio from the high unmasked level occurring as the visual system becomes more certain of target location. The level of uncertainty is indicated by the slope of sensitivity to the target as a function of target contrast in the threshold region. In these studies, high contrast masks have evoked an increase in target threshold. There have been many theories explaining this threshold increase. Some suggest that masking is the result of an intrinsic nonlinearity within a mechanism or of a contrast nonlinearity that operates directly on the output of a single mechanism. Others put the source of masking at a gain control operation which occurs when a surrounding set of mechanisms divide the response of a single mechanism by their summed response. Still others attribute the masking to noise that is multiplicative relative to the neural response signal, or noise that intrudes on the detecting mechanism from neighboring mechanisms. A detailed review of this debate is provided by the paper by Klein et al., 3016-02 in this Proceedings. Threshold elevation functions that show the relationship between mask spatial frequency and masking magnitude cannot illuminate this debate, as we demonstrated at ARVO (1994). For that study, we generated threshold elevation functions (the ratio of unmasked versus masked target threshold) for multi-channel systems using computational models that invoked either divisive inhibition, a set of transducer nonlinearities or multiplicative noise. Threshold elevation functions were indistinguishable when each masking process was assumed to have similar strength. These results led us to design the experiment presented here, which attempts to compare the effects of two of these masking processes, lateral divisive inhibition and nonlinear transducer compression.

Proceedings Article | 4 April 1997 Paper

Gray-scale adjacent pixel luminance nonlinearity compensation with three-color guns

Thom Carney, Stanley Klein

Proceedings Volume 3018, (1997) https://doi.org/10.1117/12.271591

KEYWORDS: Video, Data modeling, Raster graphics, Photometry, Analytical research, MATLAB, Sensors, Error analysis, Calibration, Visualization

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Proceedings Article | 22 April 1996 Paper

Visual masking near spatiotemporal edges

Thom Carney, Stanley Klein, Quingmin Hu

Proceedings Volume 2657, (1996) https://doi.org/10.1117/12.238736

KEYWORDS: Image compression, Visual process modeling, Visualization, Video, Video compression, Process control, Human vision and color perception, Visual system, Data modeling, Visual compression

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Proceedings Article | 20 April 1995 Paper

Improved lookup table to correct CRT adjacent pixel nonlinearity

Stanley Klein, Thom Carney, Q. James Hu

Proceedings Volume 2411, (1995) https://doi.org/10.1117/12.207536

KEYWORDS: Raster graphics, Data modeling, Displays, Video, CRTs, Image quality, MATLAB, Spatial frequencies, Solids, Visibility

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Proceedings Article | 1 May 1994 Paper

Restoration of compressed images

D. Amnon Silverstein, Stanley Klein

Proceedings Volume 2186, (1994) https://doi.org/10.1117/12.173933

KEYWORDS: Image compression, Image enhancement, Quantization, Linear filtering, Video compression, Composites, Gaussian filters, Image processing, Image filtering, Visual process modeling

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Proceedings Article | 1 May 1994 Paper

Correcting the adjacent pixel nonlinearity on video monitors

Q. James Hu, Stanley Klein

Proceedings Volume 2179, (1994) https://doi.org/10.1117/12.172696

KEYWORDS: Data modeling, Raster graphics, Video, CRTs, Amplifiers, Manufacturing, Spatial frequencies, Image quality standards, Image processing, Image quality

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Proceedings Article | 17 March 1994 Paper

Fidelity metrics and the test-pedestal approach to spatial vision

Stanley Klein

Proceedings Volume 2054, (1994) https://doi.org/10.1117/12.171142

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Proceedings Article | 8 September 1993 Paper

DCT image fidelity metric and its application to a text-based scheme for image display

D. Amnon Silverstein, Stanley Klein

Proceedings Volume 1913, (1993) https://doi.org/10.1117/12.152696

KEYWORDS: Image segmentation, Image processing, Image quality, Image display, Printing, Computing systems, Distance measurement, Receivers, Standards development, Image transmission

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Proceedings Article | 27 August 1992 Paper

Relevance of human vision to JPEG-DCT compression

Stanley Klein, D. Amnon Silverstein, Thom Carney

Proceedings Volume 1666, (1992) https://doi.org/10.1117/12.135968

KEYWORDS: Quantization, Image compression, Spatial frequencies, Visibility, Human vision and color perception, Visual process modeling, Visualization, Image processing, Contrast sensitivity, Fourier transforms

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Proceedings Article | 1 June 1991 Paper

"Perfect" displays and "perfect" image compression in space and time

Stanley Klein, Thom Carney

Proceedings Volume 1453, (1991) https://doi.org/10.1117/12.44355

KEYWORDS: Image compression, Image quality, Quantization, Wavelets, Spatial frequencies, Human vision and color perception, Image quality standards, Visual system, Visualization, Image processing

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Proceedings Article | 1 October 1990 Paper

High resolution and image compression using the discrete cosine transform

Stanley Klein

Proceedings Volume 1249, (1990) https://doi.org/10.1117/12.19671

KEYWORDS: Image compression, Spatial frequencies, Visual system, Quantization, Human vision and color perception, Visual process modeling, Image resolution, Electronic imaging, Visualization, Image transmission

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