Museum Lighting - an holistic approach

Among the environmental parameters that effect exhibited artifacts, light is the most complex and the only essential for the observer as to appreciate the artifacts, thus being one of the most critical variables of art exposure. Research on strategies for energy saving and the renovation of light destined to Heritage is examined by daylight admission and Light-Emitting Diode (LED) technology. The extended review of the literature presented below, over museum lighting, evidenced the parallel advance of lighting principles with lighting design, concerning what determines visual quality and perception. Lighting quality is an interdisciplinaryfield of research affecting human activity and under a requested task, visual performance, while at the same time improving well-being. In this sense, the role of the lighting designer is to match and rank human needs with economic and environmental aspects as to architectural principles and to translate the results into a feasible design and an efficient installation. Quality factors for art exposure, involving color fidelity and damage, along with visual perception necessitate of useful metrics through established criteria. The challenge for the museum for a holistic design of natural and artificial light is still missing of substantial metrics, even though recent findings provide some insight on the workflow to establish. Luminance-based design metrics and contrast criteria are used in this study as key strategies for museum lighting, combining comfort and viewing fine arts through advanced computer rendering. The exploration of the transition inside a daylit gallery where moving in the museum environment offers an experience for a series of adaptation changes through photopic, mesopic and dark-adapted scotopic function, along with change on the sensitivity of the spectrum. The luminance appearance and the transition adaptation in the museum field lack of research examination; the relationship of prescriptive requirements and luminance- based design has been explored initially in the field of road lighting, where the relative visual performance has been evidenced to be in the center of the CIE standard for tunnel lighting. Daylight simulation via climate-based modeling, introducing daylight filters as solar shading devices, has been proposed as the object of experimental research, connecting light “filtering” with luminance; this workflow could be applied in several fields of research considering museum environment and give responses in the preservation of artwork involving daylight. The subject of this thesis is the proposal of a ‘trama’ surface installed on windows to reduce and control daylight, studying how energy and conservation targets can be achieved. New light sources and smart control systems will integrate to a holistic approach for museum lighting design

Aerospace Medicine and Biology: A continuing bibliography with indexes, supplement 144

This bibliography lists 257 reports, articles, and other documents introduced into the NASA scientific and technical information system in July 1975

Appearance-based image splitting for HDR display systems

High dynamic range displays that incorporate two optically-coupled image planes have recently been developed. This dual image plane design requires that a given HDR input image be split into two complementary standard dynamic range components that drive the coupled systems, therefore there existing image splitting issue. In this research, two types of HDR display systems (hardcopy and softcopy HDR display) are constructed to facilitate the study of HDR image splitting algorithm for building HDR displays. A new HDR image splitting algorithm which incorporates iCAM06 image appearance model is proposed, seeking to create displayed HDR images that can provide better image quality. The new algorithm has potential to improve image details perception, colorfulness and better gamut utilization. Finally, the performance of the new iCAM06-based HDR image splitting algorithm is evaluated and compared with widely spread luminance square root algorithm through psychophysical studies

Director's discretionary fund report for fiscal year 1994

This technical memorandum contains brief technical papers describing research and technology development programs sponsored by the Ames Research Center Director's Discretionary Fund during fiscal year 1991 (October 1993 through September 1994). An appendix provides administrative information for each of the sponsored research programs

Remote Visual Observation of Real Places Through Virtual Reality Headsets

Virtual Reality has always represented a fascinating yet powerful opportunity that has attracted studies and technology developments, especially since the latest release on the market of powerful high-resolution and wide field-of-view VR headsets. While the great potential of such VR systems is common and accepted knowledge, issues remain related to how to design systems and setups capable of fully exploiting the latest hardware advances. The aim of the proposed research is to study and understand how to increase the perceived level of realism and sense of presence when remotely observing real places through VR headset displays. Hence, to produce a set of guidelines that give directions to system designers about how to optimize the display-camera setup to enhance performance, focusing on remote visual observation of real places. The outcome of this investigation represents unique knowledge that is believed to be very beneficial for better VR headset designs towards improved remote observation systems. To achieve the proposed goal, this thesis presents a thorough investigation of existing literature and previous researches, which is carried out systematically to identify the most important factors ruling realism, depth perception, comfort, and sense of presence in VR headset observation. Once identified, these factors are further discussed and assessed through a series of experiments and usability studies, based on a predefined set of research questions. More specifically, the role of familiarity with the observed place, the role of the environment characteristics shown to the viewer, and the role of the display used for the remote observation of the virtual environment are further investigated. To gain more insights, two usability studies are proposed with the aim of defining guidelines and best practices. The main outcomes from the two studies demonstrate that test users can experience an enhanced realistic observation when natural features, higher resolution displays, natural illumination, and high image contrast are used in Mobile VR. In terms of comfort, simple scene layouts and relaxing environments are considered ideal to reduce visual fatigue and eye strain. Furthermore, sense of presence increases when observed environments induce strong emotions, and depth perception improves in VR when several monocular cues such as lights and shadows are combined with binocular depth cues. Based on these results, this investigation then presents a focused evaluation on the outcomes and introduces an innovative eye-adapted High Dynamic Range (HDR) approach, which the author believes to be of great improvement in the context of remote observation when combined with eye-tracked VR headsets. Within this purpose, a third user study is proposed to compare static HDR and eye-adapted HDR observation in VR, to assess that the latter can improve realism, depth perception, sense of presence, and in certain cases even comfort. Results from this last study confirmed the author expectations, proving that eye-adapted HDR and eye tracking should be used to achieve best visual performances for remote observation in modern VR systems

Change blindness: eradication of gestalt strategies

Arrays of eight, texture-defined rectangles were used as stimuli in a one-shot change blindness (CB) task where there was a 50% chance that one rectangle would change orientation between two successive presentations separated by an interval. CB was eliminated by cueing the target rectangle in the first stimulus, reduced by cueing in the interval and unaffected by cueing in the second presentation. This supports the idea that a representation was formed that persisted through the interval before being 'overwritten' by the second presentation (Landman et al, 2003 Vision Research 43149–164]. Another possibility is that participants used some kind of grouping or Gestalt strategy. To test this we changed the spatial position of the rectangles in the second presentation by shifting them along imaginary spokes (by ±1 degree) emanating from the central fixation point. There was no significant difference seen in performance between this and the standard task [F(1,4)=2.565, p=0.185]. This may suggest two things: (i) Gestalt grouping is not used as a strategy in these tasks, and (ii) it gives further weight to the argument that objects may be stored and retrieved from a pre-attentional store during this task

Aerospace Medicine and Biology: A continuing bibliography with indexes

This bibliography lists 253 reports, articles, and other documents introduced into the NASA scientific and technical information system in October 1975