scholarly journals Light Fields for Face Analysis

Sensors ◽  
2019 ◽  
Vol 19 (12) ◽  
pp. 2687 ◽  
Author(s):  
Chiara Galdi ◽  
Valeria Chiesa ◽  
Christoph Busch ◽  
Paulo Lobato Correia ◽  
Jean-Luc Dugelay ◽  
...  
Keyword(s):  
Light Field ◽  
Dimensional Space ◽  
Field Vector ◽  
Attack Detection ◽  
Light Fields ◽  
Face Analysis ◽  
Facial Landmark Detection ◽  
Plenoptic Function ◽  
3 Dimensional ◽  
Future Challenges

The term “plenoptic” comes from the Latin words plenus (“full”) + optic. The plenoptic function is the 7-dimensional function representing the intensity of the light observed from every position and direction in 3-dimensional space. Thanks to the plenoptic function it is thus possible to define the direction of every ray in the light-field vector function. Imaging systems are rapidly evolving with the emergence of light-field-capturing devices. Consequently, existing image-processing techniques need to be revisited to match the richer information provided. This article explores the use of light fields for face analysis. This field of research is very recent but already includes several works reporting promising results. Such works deal with the main steps of face analysis and include but are not limited to: face recognition; face presentation attack detection; facial soft-biometrics classification; and facial landmark detection. This article aims to review the state of the art on light fields for face analysis, identifying future challenges and possible applications.

Association algorithm with bearing-only measurements in 3-dimensional space

2009 ◽  
Author(s):  
Xiu Jianjuan ◽  
Li Yuli ◽  
He You ◽  
Wang Guohong
Keyword(s):  
Dimensional Space ◽  
3 Dimensional ◽  
Association Algorithm

Triharmonic Riemannian submersions from 3-dimensional space forms

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Tomoya Miura ◽  
Shun Maeta
Keyword(s):  
Existence Theorem ◽  
Space Form ◽  
Dimensional Space ◽  
Riemannian Submersion ◽  
Partial Answer ◽  
Riemannian Submersions ◽  
Space Forms ◽  
3 Dimensional

Abstract We show that any triharmonic Riemannian submersion from a 3-dimensional space form into a surface is harmonic. This is an affirmative partial answer to the submersion version of the generalized Chen conjecture. Moreover, a non-existence theorem for f -biharmonic Riemannian submersions is also presented.

The early attentional pancake: Lack of selection in depth for rapid exogenous cueing

2021 ◽  
Author(s):  
Ryan Edward O'Donnell ◽  
Kyrie Murawski ◽  
Ella Herrmann ◽  
Jesse Wisch ◽  
Garrett D. Sullivan ◽  
...  
Keyword(s):  
Reaction Time ◽  
Binocular Disparity ◽  
Dimensional Space ◽  
Exogenous Attention ◽  
3 Dimensional ◽  
Exogenous Cueing ◽  
Different Depths ◽  
Depth Cueing ◽  
The Difference ◽  
Attentional Selectivity

There have been conflicting findings on the degree to which exogenous/reflexive visual attention is selective for depth, and this issue has important implications for attention models. Previous findings have attempted to find depth-based cueing effects on such attention using reaction time measures for stimuli presented in stereo goggles with a display screen. Results stemming from such approaches have been mixed, depending on whether target/distractor discrimination was required. To help clarify the existence of such depth effects, we have developed a paradigm that measures accuracy rather than reaction time in an immersive virtual-reality environment, providing a more appropriate context of depth. Four modified Posner Cueing paradigms were run to test for depth-specific attentional selectivity. Participants fixated a cross while attempting to identify a rapidly masked letter that was preceded by a cue that could be valid in depth and side, depth only, or side only. In Experiment 1, a potent cueing effect was found for side validity and a weak effect was found for depth. Experiment 2 controlled for differences in cue and target sizes when presented at different depths, which caused the depth validity effect to disappear entirely even though participants were explicitly asked to report depth and the difference in virtual depth was extreme (20 vs 300 meters). Experiments 3a and 3b brought the front depth plane even closer (1 m) to maximize effects of binocular disparity, but no reliable depth cueing validity was observed. Thus, it seems that rapid/exogenous attention pancakes 3-dimensional space into a 2-dimensional reference frame.

scholarly journals Review of light field technologies

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Shuyao Zhou ◽  
Tianqian Zhu ◽  
Kanle Shi ◽  
Yazi Li ◽  
Wen Zheng ◽  
...  
Keyword(s):  
Light Field ◽  
Depth Estimation ◽  
Industrial Applications ◽  
Light Fields ◽  
Physical Concept ◽  
Network Bandwidth ◽  
The Past ◽  
Art Research ◽  
Near Future ◽  
Field Imaging

AbstractLight fields are vector functions that map the geometry of light rays to the corresponding plenoptic attributes. They describe the holographic information of scenes by representing the amount of light flowing in every direction through every point in space. The physical concept of light fields was first proposed in 1936, and light fields are becoming increasingly important in the field of computer graphics, especially with the fast growth of computing capacity as well as network bandwidth. In this article, light field imaging is reviewed from the following aspects with an emphasis on the achievements of the past five years: (1) depth estimation, (2) content editing, (3) image quality, (4) scene reconstruction and view synthesis, and (5) industrial products because the technologies of lights fields also intersect with industrial applications. State-of-the-art research has focused on light field acquisition, manipulation, and display. In addition, the research has extended from the laboratory to industry. According to these achievements and challenges, in the near future, the applications of light fields could offer more portability, accessibility, compatibility, and ability to visualize the world.

Dynamical Variation of Weierstrass-Mandelbrot Function in Higher Dimensional Space

2013 ◽  
Vol 470 ◽  
pp. 767-771
Author(s):  
L. Zhang ◽  
Shu Tang Liu
Keyword(s):  
Hurst Exponent ◽  
Dimensional Space ◽  
Dynamical Behavior ◽  
Fractal Dimensions ◽  
Statistical Characteristics ◽  
3 Dimensional ◽  
Higher Dimensional ◽  
Complex Phenomena ◽  
Real Complex

Many real complex phenomena are related with Weierstrass-Mandelbrot function (WMF). Most researches focus on the systems as parameters fixed, such as calculations of its different fractal dimensions or the statistical characteristics of its generalized form and so on. Moreover, real systems always change according to different environments, so that to study the dynamical behavior of these systems as parameters change is important. However, there is few results about this aim. In this paper, we propose simulated results for the effects of parameters changeably on the graph of WMF in higher dimensional space. In addition, the relationships between the Hurst exponent of WMF and its parameters dynamically in 2-and 3-dimensional spaces are also given.

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