Visual gamma correction for LCD displays

Xiao, Kaida; Fu, Chenyang; Karatzas, Dìmosthenis; Wuerger, Sophie

doi:10.1016/j.displa.2010.09.003

Cited by 18 publications

(20 citation statements)

References 11 publications

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“…The display’s gamma/brightness/contrast can be visually calibrated. 5 , 6 Visual calibration is sufficiently reliable to be used as an alternative to calibration using an expensive photometer. 5 The software uses a gray scale step wedge for display adjustment.…”

Section: Methodsmentioning

confidence: 99%

Visual field examination method using virtual reality glasses compared with the Humphrey perimeter

Tsapakis¹,

Papaconstantinou²,

Diagourtas³

et al. 2017

OPTH

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PurposeTo present a visual field examination method using virtual reality glasses and evaluate the reliability of the method by comparing the results with those of the Humphrey perimeter.Materials and methodsVirtual reality glasses, a smartphone with a 6 inch display, and software that implements a fast-threshold 3 dB step staircase algorithm for the central 24° of visual field (52 points) were used to test 20 eyes of 10 patients, who were tested in a random and consecutive order as they appeared in our glaucoma department. The results were compared with those obtained from the same patients using the Humphrey perimeter.ResultsHigh correlation coefficient (r=0.808, P<0.0001) was found between the virtual reality visual field test and the Humphrey perimeter visual field.ConclusionVisual field examination results using virtual reality glasses have a high correlation with the Humphrey perimeter allowing the method to be suitable for probable clinical use.

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Section: Methodsmentioning

confidence: 99%

Visual field examination method using virtual reality glasses compared with the Humphrey perimeter

Tsapakis¹,

Papaconstantinou²,

Diagourtas³

et al. 2017

OPTH

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“…Phase linearity correction is an essential step for phase modulation panels. This is similar to the gamma correction for linear amplitude modulation in LC displays [42], but is a more complex process, covering the full 2 π radians phase. The linear phase response is a key criterion for satisfying computer-generated hologram (CGH) patterns calculated on the basis of the iterative Fourier transform algorithm (IFTA) or Fresnel (near-field)/Fraunhofer (far-field) diffraction equations, derived from scalar diffraction theory.…”

Section: Phase Linearitymentioning

confidence: 68%

Pursuing High Quality Phase-Only Liquid Crystal on Silicon (LCoS) Devices

et al. 2018

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Fine pixel size and high-resolution liquid crystal on silicon (LCoS) backplanes have been developed by various companies and research groups since 1973. The development of LCoS is not only beneficial for full high definition displays but also to spatial light modulation. The high-quality and well-calibrated panels can project computer generated hologram (CGH) designs faithfully for phase-only holography, which can be widely utilized in 2D/3D holographic video projectors and components for optical telecommunications. As a result, we start by summarizing the current status of high-resolution panels, followed by addressing issues related to the driving frequency (i.e., liquid crystal response time and hardware interface). LCoS panel qualities were evaluated based on the following four characteristics: phase linearity control, phase precision, phase stability, and phase accuracy.A phase-only spatial light modulator can be used as a key optical element for displays, adaptive optics for sensing, lithography, and telecommunication, as shown in Figure 2. The linearity of phase modulation, response time, phase precision, and phase stability are key characteristics for appraising or selecting phase-only LCoS-SLM panels for the applications designed. However, it is difficult to obtain a single LCoS possessing all the desired features for all applications. Their specification and performance optimization are application-driven. For example, response time is the current limitation in a holographic display. It may be more important than phase stability,

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“…The nonlinear response functions of the LCD screen and CCD camera will introduce nonlinear error to the captured fringe pattern [9][10][11][12]20 and cause error in the demodulated phase. The nontelecentric imaging of the CCD camera will introduce another kind of nonlinear error (aberration) to the measurement.…”

Section: Phase Error Sources In Phase Measuring Deflectometrymentioning

confidence: 99%

Phase error analysis and reduction in phase measuring deflectometry

Wu¹,

Yue²,

Yi³

et al. 2015

Opt. Eng

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In phase measuring deflectometry (PMD), the inspection accuracy of the defects and height of the specular surface are related to the level of phase errors. The usage of numeric integration in reconstructing the shape and the defocusing capture of the fringe pattern, which will amplify the phase errors, make error discussion more significant in PMD than other shape measurement techniques. Phase error analysis and reduction in PMD are presented. The random noises, nonlinear response function, the nontelecentric imaging of the charge-coupled device camera, and the nonlinear response function of the liquid crystal display screen are the main phase error sources in PMD. The analytical relation between the random phase error and its influence factors in PMD is deduced. From the relation formulation, the influence factors of random phase error are analyzed, and the results are proven by the simulation and experiment. A possible phase error-reduction method, which integrates several methods for congeneric errors in fringe projection profilometry, is investigated to reduce phase errors in PMD. This composite method is proven to have a good performance by a plane mirror experiment.

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Visual gamma correction for LCD displays

Cited by 18 publications

References 11 publications

Visual field examination method using virtual reality glasses compared with the Humphrey perimeter

Visual field examination method using virtual reality glasses compared with the Humphrey perimeter

Pursuing High Quality Phase-Only Liquid Crystal on Silicon (LCoS) Devices

Phase error analysis and reduction in phase measuring deflectometry

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