Spatial properties of light fields in natural scenes

Mury, Alexander A.; Pont, Sylvia C.; Koenderink, Jan J.

doi:10.1145/1272582.1272617

Cited by 6 publications

(5 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In conclusion, the human visual system appears to be idiosyncratic in that it easily groups unidirectional, convergent, and divergent illuminance flow patterns but fully ignores rotational and deformation patterns. This is the case even though the first-order patterns all occur in the natural environment (Mury et al, 2007 , 2009b ). This “selective blindness” is reminiscent of the inability to be visually aware of the conventional stimulus pattern as anything else but cap or cup (Wagemans et al, 2010 ).…”

Section: Overall Conclusionmentioning

confidence: 99%

“…The light field in a realistic scene has numerous “singular points”, which are of various qualitatively different natures. In planar sections, one has cases of convergent or divergent, whirl (rotational) and deformation fields (Mury et al, 2007 ). An example is shown in Figure A1 .…”

Section: Figure A1mentioning

confidence: 99%

“…Recently, we have found (van Doorn, Koenderink, & Wagemans, 2011 ) that this “synchronization” (a kind of “grouping”) also occurs for divergent and convergent illuminance flows ( Figure 2 , third from left) but not for rotational illuminance flows ( Figure 2 , right). This is interesting, because all first-order singularities of the illuminance flow field (i.e., divergence, rotational, and deformation fields) occur in the daily environment (Mury, Pont, & Koenderink, 2007 , 2009a , 2009b ). Thus, the apparent selective sensitivity appears perhaps surprising.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Awareness of the Light Field: The Case of Deformation

et al. 2012

Self Cite

View full text Add to dashboard Cite

Human observers group local shading patterns into global super-patterns that appear to be illuminated in some unitary fashion. Many years ago, this was noticed for the case of uniform, unidirectional illumination. Recently, we found that it also applies to convergent and divergent illumination flows, but that human observers are blind to rotational light flow patterns (in the sense of being unable to group the local shading patterns). We now report that human observers are also blind to deformation patterns. This is perhaps interesting because convergent, divergent, rotational, and deformation patterns all occur in natural light fields. This is an idiosyncrasy of the human visual system, on par with the fact that visual awareness fails to present the observer with saddle shapes.

show abstract

Section: Overall Conclusionmentioning

confidence: 99%

Section: Figure A1mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Awareness of the Light Field: The Case of Deformation

et al. 2012

Self Cite

View full text Add to dashboard Cite

show abstract

“…It is referred to as a "squash tensor" [7]. In natural scenes, the low-order contributions to light fields show very systematic and smooth behavior varying very slowly from one point of the scene to another [7,18].…”

Section: Previous Workmentioning

confidence: 99%

Representing the light field in finite three-dimensional spaces from sparse discrete samples

2009

Self Cite

View full text Add to dashboard Cite

We present a method for measurement and reconstruction of light fields in finite spaces. Using a custommade device called a plenopter, we can measure spatially and directionally varying radiance distribution functions from a real-world scene up to their second-order spherical harmonics approximations. Interpolating between measurement points, we can recover this function for arbitrary points of a scene. We visualized the global structure of the light field using light tubes, which gives an intuitive description of the flux propagation throughout three-dimensional scenes and provides information about the quality of light in the scenes. Our second-order reconstructions are sufficient to render convex matte objects and therefore have a direct interest for computer graphics applications.

show abstract

“…However, there is almost nothing comparable at hand in the scientific literature, not even at a classificatory or descriptive level. Science has extensively developed analysis of the objective, radiometric aspects of light such as radiance, luminance, and luminous environment, describing the objective illumination of the light field from the physical ( natural ) viewpoint and its properties (Fleming, Dror, & Adelson, 2003; Morgenstern, Geisler, & Murray, 2014; Morgenstern, Murray, & Geisler, 2010, 2011; Mury, Pont, & Koenderink, 2007, 2009; Olkkonen & Brainard, 2010; Pont & Koenderink, 2007; Xia, Pont, & Heynderinckx, 2014b); and its perception from a psychophysical viewpoint (Adelson & Bergen, 1991; Kartashova, Sekulovski, de Ridder, te Pas, & Pont, 2016; Koenderink, Pont, van Doorn, Kappers, & Todd, 2007; Maloney, 2002; Maloney, Gerhard, Boyaci, & Doerschner, 2010; Toscani, Gegenfurtner, & Doerschner, 2017; for a systematic review, from the inferential viewpoint, see Schirillo, 2013). Unfortunately, however, there has been no similar development in the analysis of perceived illumination in phenomenological terms, probably because the phenomenon as such is difficult to address and to identify using current approaches and methodologies, because it is characterized by a set of dimensions that apparently evade a quantitative explanation.…”

Section: Introductionmentioning

confidence: 99%

Sensual Light? Subjective Dimensions of Ambient Illumination

et al. 2018

View full text Add to dashboard Cite

This work concerns the subjective impression of perceived illumination. The purpose of the study is to test attributes expressing qualitative experiences referring to ambient lighting that can be applied as descriptors. Seventy participants viewed an actual model room, with the fourth wall removed (viewing booth). Walls, floor, and ceiling were achromatic. Two achromatic cubes were placed inside the room: One was a reflectance increment to the walls, the other a decrement. The room was illuminated by two different light sources, Artificial Daylight (D65) or Tungsten Filament (F), the order of which was randomized across participants. The participants' task was to evaluate ambient illumination for each light source. A semantic differential method was employed with 27 pairs of adjectives on 1 to 7 rating scales, categorized in three groups: characteristics of atmosphere, time, and cross-modal. Only the ratings of nine pairs of adjectives were not influenced by the type of illumination. The most differentiated couples under different illuminants were hot/cold and modern/old, but large differences also appeared with the following couples: hard/soft, technological/primitive, summery/wintry, warm/cool, sensual/frigid, natural/artificial, and hospitable/inhospitable. The hypothesis that there would be consistency among the subjects in evaluations of the characteristics tested and that these would be differently perceived under different illuminants was confirmed. The results show that it is possible to identify subjective perceived illumination as a phenomenon endowed with specific filling-in qualities and that as a perceptual experience it can be categorized, with implications for application in architecture and design.

show abstract

Spatial properties of light fields in natural scenes

Cited by 6 publications

References 2 publications

Awareness of the Light Field: The Case of Deformation

Awareness of the Light Field: The Case of Deformation

Representing the light field in finite three-dimensional spaces from sparse discrete samples

Sensual Light? Subjective Dimensions of Ambient Illumination

Contact Info

Product

Resources

About