Common and relative components of reflected light as information about the illumination, colour, and three‐dimensional form of objects

Bergström, Sten Sture

doi:10.1111/j.1467-9450.1977.tb00275.x

Cited by 69 publications

(60 citation statements)

References 19 publications

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“…The point is that, in these cases, a decision about lightness is the same as a decision about depth. Bergstrom (1977) has reached similar conclusions using an analysis of the kind Johansson has used for motion. Bergstrom presented observers with a pattern of luminance gradients that might be described as a decreasing series of luminance steps, although the step changes were gradual, not sharp.…”

Section: Differences From Previous Studiessupporting

confidence: 48%

When does perceived lightness depend on perceived spatial arrangement?

Gilchrist

1980

Perception & Psychophysics

211

146

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Experiments have recently been reported in which a decisive change in perceived lightness was produced by a change in perceived spatial position, with no important change in the retinal image. A number of previous studies had found little or no such effect. Experiments of the kind that produced these effects and of the kind that do not produce these effects are presented here. The main differences between these two kinds of experiments are discussed. One difference is whether the display allows the target to be part of one ratio in one spatial position but another in the other spatial position. Another difference concerns the range of luminances within the display. Also discussed are the implications of these findings for cognitive vs. S-R theories, the order of processing depth and lightness, laboratory data vs. experience, the role of lateral inhibition in lightness perception, and theories of lightness perception in general.

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Section: Differences From Previous Studiessupporting

confidence: 48%

When does perceived lightness depend on perceived spatial arrangement?

Gilchrist

1980

Perception & Psychophysics

211

146

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“…The concept of the two-dimensional achromatic colour manifold and the phenomenon of illumination discounting prompts us to take a fresh look at some old controversial issues in lightness perception, such as, for example, the intrinsic-images-based approach, which suggests that the retinal illuminance pattern is analysed into two component images: an illumination image and a lightness image (see, e.g., Adelson & Pentland, 1996;Arend, 1994;Barrow & Tenenbaum, 1978;Bergstrom, 1977;Gilchrist, 1979). This approach implies, implicitly or explicitly, that each luminance edge is classified as either a lightness or an illumination edge.…”

Section: Discussionmentioning

confidence: 99%

Lightness constancy and illumination discounting

Logvinenko

Tokunaga

2011

Atten Percept Psychophys

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Contrary to the implication of the term "lightness constancy", asymmetric lightness matching has never been found to be perfect unless the scene is highly articulated (i.e., contains a number of different reflectances). Also, lightness constancy has been found to vary for different observers, and an effect of instruction (lightness vs. brightness) has been reported. The elusiveness of lightness constancy presents a great challenge to visual science; we revisit these issues in the following experiment, which involved 44 observers in total. The stimuli consisted of a large sheet of black paper with a rectangular spotlight projected onto the lower half and 40 squares of various shades of grey printed on the upper half. The luminance ratio at the edge of the spotlight was 25, while that of the squares varied from 2 to 16. Three different instructions were given to observers: They were asked to find a square in the upper half that (i) looked as if it was made of the same paper as that on which the spotlight fell (lightness match), (ii) had the same luminance contrast as the spotlight edge (contrast match), or (iii) had the same brightness as the spotlight (brightness match). Observers made 10 matches of each of the three types. Great interindividual variability was found for all three types of matches. In particular, the individual Brunswik ratios were found to vary over a broad range (from .47 to .85). That is, lightness matches were found to be far from veridical. Contrast matches were also found to be inaccurate, being on average, underestimated by a factor of 3.4. Articulation was found to essentially affect not only lightness, but contrast and brightness matches as well. No difference was found between the lightness and luminance contrast matches. While the brightness matches significantly differed from the other matches, the difference was small. Furthermore, the brightness matches were found to be subject to the same interindividual variability and the same effect of articulation. This leads to the conclusion that inexperienced observers are unable to estimate both the brightness and the luminance contrast of the light reflected from real objects lit by real lights. None of our observers perceived illumination edges purely as illumination edges: A partial Gelb effect ("partial illumination discounting") always took place. The lightness inconstancy in our experiment resulted from this partial illumination discounting. We propose an account of our results based on the two-dimensionality of achromatic colour. We argue that large interindividual variations and the effect of articulation are caused by the large ambiguity of luminance ratios in the stimulus displays used in laboratory conditions.

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“…They follow the logic of inverse optics. Bergström (1977) has a nice theory that the image is decomposed into common and relative components in the reflected light, very much analogous to the theory of motion perception proposed by his mentor Gunnar Johansson (1977). Adelson and Pentland (1996) came along later on with a very similar model but couched in a wonderful theater workshop metaphor.…”

Section: Single-stage Models Of Lightnessmentioning

confidence: 99%

Theoretical Approaches to Lightness and Perception

Gilchrist

2015

Perception

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Abstract. Theories of lightness, like theories of perception in general, can be categorized as highlevel, low-level, and mid-level. However, I will argue that in practice there are only two categories: one-stage mid-level theories, and two-stage low-high theories. Low-level theories usually include a high-level component and high-level theories include a low-level component, the distinction being mainly one of emphasis. Two-stage theories are the modern incarnation of the persistent sensation/ perception dichotomy according to which an early experience of raw sensations, faithful to the proximal stimulus, is followed by a process of cognitive interpretation, typically based on past experience. Like phlogiston or the ether, raw sensations seem like they must exist, but there is no clear evidence for them. Proximal stimulus matches are postperceptual, not read off an early sensory stage. Visual angle matches are achieved by a cognitive process of flattening the visual world. Likewise, brightness (luminance) matches depend on a cognitive process of flattening the illumination. Brightness is not the input to lightness; brightness is slower than lightness. Evidence for an early (< 200 ms) mosaic stage is shaky. As for cognitive influences on perception, the many claims tend to fall apart upon close inspection of the evidence. Much of the evidence for the current revival of the 'new look' is probably better explained by (1) a natural desire of (some) subjects to please the experimenter, and (2) the ease of intuiting an experimental hypothesis. High-level theories of lightness are overkill. The visual system does not need to know the amount of illumination, merely which surfaces share the same illumination. This leaves mid-level theories derived from the gestalt school. Here the debate seems to revolve around layer models and framework models. Layer models fit our visual experience of a pattern of illumination projected onto a pattern of reflectance, while framework models provide a better account of illusions and failures of constancy. Evidence for and against these approaches is reviewed.

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Common and relative components of reflected light as information about the illumination, colour, and three‐dimensional form of objects

Cited by 69 publications

References 19 publications

When does perceived lightness depend on perceived spatial arrangement?

When does perceived lightness depend on perceived spatial arrangement?

Lightness constancy and illumination discounting

Theoretical Approaches to Lightness and Perception

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