Complementary Hues Research Articles

Façade Integrated Photovoltaics design for high-rise buildings with balconies, balancing daylight, aesthetic and energy productivity performance

Façade Integrated Photovoltaics (FIPV) is a promising strategy to deploy solar energy in the built environment and to achieve the carbon-neutral goals of society. As standing out areas of façade, cantilevered balconies are ideal for FIPV application. However, the balcony shadings can also influence the solar potential on other parts of facades and the interior daylight performance. There is an urgent need for systematic architectural studies to promote FIPV application for buildings with balconies. This research aims to develop a holistic architectural method supporting the integrative design of FIPV for residential high-rise buildings. Firstly, balcony prototypes and position arrangements (aligned, staggered and side) for high-rises were proposed, with Trondheim city in Norway as a case study. Then daylight and solar radiation analysis were conducted through a series of simulations. Based on aesthetic strategies, coloured FIPV designs were proposed subsequently and tested in an online survey. Finally, theoretical energy productivity calculations were conducted. The results showed that side balconies arrangement could provide the best performance in interior daylight and solar energy harvest aspects, and FIPV designs with partial balcony railing areas in complementary hues were the most aesthetically preferred type. The estimated annual energy generated by FIPV together with roof-integrated PV (black) can cover up to 60% of household energy consumption of an 11-floor high-rise. The study provided a novel integrative design method supporting the FIPV application for high-rise with balconies from architectural perspectives, which can balance the performance in aspects of façade aesthetic, interior daylight, and energy productivity.

Perceptual holistic color combination analysis of Papilionidae butterflies as aesthetic objects.

In this study, we clarified the holistic color combination rules of human-preferred Papilionidae butterflies by examining the hue, lightness, and chroma. A set of 118 Papilionidae butterfly images used in our previous study was analyzed. These images were classified via hierarchical density-based spatial clustering based on perceptual similarities of colors that were obtained from a subjective image classification experiment. The color combinations of the clustered images were determined based on representative colors that were analyzed by a Gaussian mixture model with minimum message length and the color combination types defined in our previous study. Consequently, we obtained the following holistic color combination rules for Papilionidae: 1) contrasting lightness, similar chroma, and similar hue, 2) contrasting lightness, contrasting chroma, and similar hue, 3) similar lightness, similar chroma, and complementary hue, and 4) similar lightness, similar chroma, and similar hue. These rules suggest that minority color harmony theories are valid under particular conditions.

Ensemble coding of color and luminance contrast.

Ensemble coding has been demonstrated for many attributes including color, but the metrics on which this coding is based remain uncertain. We examined ensemble percepts for stimulus sets that varied in chromatic contrast between complementary hues, or that varied in luminance contrast between increments and decrements, in both cases focusing on the ensemble percepts for the neutral gray stimulus defining the category boundary. Each ensemble was composed of 16 circles with four contrast levels. Observers saw the display for 0.5 s and then judged whether a target contrast was a member of the set. False alarms were high for intermediate contrasts (within the range of the ensemble) and fell for higher or lower values. However, for ensembles with complementary hues, gray was less likely to be reported as a member, even when it represented the mean chromaticity of the set. When the settings were repeated for luminance contrast, false alarms for gray were higher and fell off more gradually for out-of-range contrasts. This difference implies that opposite luminance polarities represent a more continuous perceptual dimension than opponent-color variations, and that "gray" is a stronger category boundary for chromatic than luminance contrasts. For color, our results suggest that ensemble percepts reflect pooling within rather than between large hue differences, perhaps because the visual system represents hue differences more like qualitatively different categories than like quantitative differences within an underlying color "space." The differences for luminance and color suggest more generally that ensemble coding for different visual attributes might depend on different processes that in turn depend on the format of the visual representation.

Pure Painting and Mottled Colour

On the eve of World War I, Guillaume Apollinaire announced the birth of ‘pure painting’. Scholars have typically understood this as an early version of mid-century theories of abstract art; however, that interpretation ignores the poet’s close association with Robert and Sonia Delaunay. Those artists were deeply influenced by M. E. Chevreul, a nineteenth-century colour theorist who showed that complementary hues appear more pure when seen simultaneously. Most often discussed in relation to the phenomenological changes that occur when red and green are viewed side-by-side, simultaneous contrast suggests an alternative view of purity. For the Delaunays, pure painting was not a retreat from the world, but a way of making its dichotomies and conflicts more visible.

Impact of the starting point chromaticity on memory color matching accuracy.

In this study, the impact of starting point chromaticity and number of observers on memory color matching results was investigated. Matching data were obtained for 3 objects (neutral grey cube, yellow lemon and green apple) under a neutral white and a yellow background illumination. Memory color matchings were made for ten starting points of which eight chromaticities were symmetrically distributed along the hue circle and centered at the equal energy white (EEW) chromaticity of the neutral white background illumination; one starting point at the EEW chromaticity and one with the same chromaticity as the background. The matching track from starting point to the memory matched chromaticity was also recorded. It did not tend to cross over the central region towards the complementary hue, especially for experienced observers. The results also demonstrated a significant starting point bias, whereby the matched chromaticities were biased towards the chromaticity of the starting point. Starting point bias can be minimized by selecting three starting points symmetrically distributed around the expected memory color chromaticity. Furthermore, at least, ten observers are needed to achieve stable results for the grey cube and yellow lemon. For the green apple, the results are less conclusive and around 40 observers would be needed to obtain a stable average estimate for the chromaticity of the memory color. The large inter-observer variation may result from cultural differences or from natural variations in the "green" apple appearance. This study provides a well-founded guidance for future application of the memory color matching method.

Functional Colors: The Varied Applications of Complementary Hues

Film scholars in recent years have identified a differentiated landscape of color systems in terms of looks and processes that represent natural color phenomena with increasing fidelity and automation. Here, I propose extending the concept of film colors to techniques that deploy colors in order to produce effects that do not show color but use it for other means. Stereoscopy and compositing are two applications from the 1920s that employed complementary colors and that were often developed by the same parties that helped create representational color systems. These correlations have, thus far, not been the subject of color studies because research is organized according to the intended applications of techniques and does not follow the work of the technicians and artists. I argue that techniques that use colors for other purposes have been ignored due to a focus on color primarily in relation to human perception and understanding. To extend the scope of research to nonrepresentational applications of color, as I propose, thus implies a methodological critique of the existing discourse on color as being anthropocentric, that is, as ignoring functional relationships of colors that do not relate to humans.

Color harmony in two‐piece garments

AbstractUsing a categorical scale of 10 U, we have assessed color harmony in two‐piece garments (jackets‐trousers) considering a vicenarian and a quinquagenarian style. The experiment was performed by a panel of 59 Chinese observers (26 males and 33 females) with normal color vision and ages ranging 20–78 years, considering 300 color combinations for each of the two styles. For a given color combination, comparing results in the vicenarian/quinquagenarian styles for female/male observers, and observers below/above 45 years old, we found generally higher harmony scores for the vicenarian style, male observers, and observers older than 45 years. We found statistically significant differences (Welch two‐sample t test, P < 0.001) between color‐harmony results for the vicenarian and quinquagenarian styles, as well as considering the scores reported both by male/female observers and by observers below/above 45 years old. We propose a very simple lineal model fitting our current results with an average root mean square error (RMSE) of 0.70 U in our 10‐unit scale, which is below the one achieved by other complex models previously proposed, and also below the inter‐ and intra‐observer variability in our experiment. From our total experimental results, each of the five traditional color‐harmony principles (complementary hues and equal lightness, chroma, tone, and hue) was found to be valid at a low percentage (53–58% of the cases). © 2016 Wiley Periodicals, Inc. Col Res Appl, 42, 498–511, 2017

Visual Associative Memory Simulates the McCollough Effect

The McCollough effect (ME) refers to the phenomenon that, after a few minutes' exposure to gratings differing in both orientation and colour, subjects perceive similarly oriented achromatic gratings as if they were tinted with complementary hues. The traditional explanation of the ME as an adaptation of detectors selective for colour and orientation suffers from a number of inconsistencies: (i) the ME lasts much longer than ordinary adaptation, the decay of the effect being completely arrested during a night's sleep, or by occluding the eye for a long time; (ii) the strength of the ME is practically independent of the intensity of the adapting light; and (iii) a set of related pattern-contingent aftereffects discovered later would require, for explanation on similar lines, new detectors specific to other patterns. These properties can be explained, however, in the framework of associative memory and novelty filters. A computational model has been developed which consists of (i) an input layer of two (left and right eyes) square matrices with two analog receptors (red and green) in each pixel; (ii) an isomorphic associative neural layer, each neuron being synaptically connected with all receptors of both eyes; and (iii) an output layer (novelty filter). Modification of synaptic efficacies conforms to the Hebb learning rule. After a few presentations of coloured gratings the model displays the ME, which is slowly destroyed by subsequent presentations of random pictures. With a sufficiently large receptor matrix the effect lasts a thousand times longer than the period of learning. Continuous darkness does not change the strength of the effect. Like the real ME, the model does not display interocular transfer, but with other adapting patterns it shows the disparity-contingent colour aftereffect (thus confirming the connections with both eyes). The model can account for different pattern-contingent colour aftereffects without assuming any predetermined specific detectors. Such detectors are constructed in the course of adaptation to specific stimuli (gratings).

Effects of colour adaptation and stimulus size on the detection of chromatic deviations from achromatic as a function of eccentricity in man

By using constant size and M-scaled stimuli (the stimulus size was magnified towards the visual field periphery in inverse proportion to the lowest local sampling density of the human retina) we measured the thresholds for perceiving the complementary colours of blue, green and red (i.e. yellow, purple or blue-green) under chromatic adaptation at the eccentricities of 0-15 degrees in the nasal visual field. The CIE 1931 (x, y) chromaticity coordinates corresponding to complementary hue perception were subtracted from the chromaticity coordinates of achromatic threshold. The difference was found to be constant irrespective of stimulus size and eccentricity. This means that the perception of chromatic deviation from achromatic under chromatic adaptation is independent of stimulus size and eccentricity.

Surface shape and curvature scales

The classical surface curvature measures, such as the Gaussian and the mean curvature at a point of a surface, are not very indicative of local shape. The two principal curvatures (taken as a pair) are more informative, but one would prefer a single shape indicator rather than a pair of numbers. Moreover, the shape indicator should preferably be independent of the size i.e. the amount of curvature, as distinct from the type of curvature. We propose two novel measures of local shape, the ‘curvedness’ and the ‘shape index’. The curvedness is a positive number that specifies the amount of curvature, whereas the shape index is a number in the range [−1, +1] and is scale invariant. The shape index captures the intuitive notion of ‘local shape’ particularly well. The shape index can be mapped upon an intuitively natural colour scale. Two complementary shapes (like stamp and mould) map to complementary hues. The symmetrical saddle (which is very special because it is self-complementary) maps to white. When a surface is tinted according to this colour scheme, this induces an immediate perceptual segmentation of convex, concave, and hyperbolic areas. We propose it as a useful tool in graphics representation of 3D shape.

Influence of chroma and hue on spatial balance of color Pairs

AbstractEarlier research has shown that the relative chroma (saturation) of color pairs affects the relative areas of those colors that appear balanced in a predictable way. Small areas of high chroma balance large areas of low chroma. The present study shows that this chroma effect is independent of the background the colors were viewed against, and relatively independent of the hues involved. In particular, the chroma effect is as strong for hue pairs adjacent or intermediate on the color circle as for complementary hues. Finally, this study compared Munsell's theory of spatial balance to that of Moon and Spencer, finding better agreement with the former.

Influence of Chroma on Spatial Balance of Complementary Hues

In 1905, Munsell proposed that if the relative areas of two colors are adjusted so that they mix to produce a neutral gray on a spinning Maxwell disk, these colors should appear balanced when juxtaposed with the same relative areas in a composition. This law of "inverse ratios of area" indicates that hues of low chroma should require larger relative areas to balance complementary hues of higher chroma. Several experiments have compared colors of varying chroma in terms of apparent weight, but none have assessed the validity of Munsell's law directly. A group of artists and a group of nonartists with no prior training in the use of color adjusted a panel until the relative areas of two complementary colors appeared balanced. Within-subject correlations between actual settings and theoretical predictions were predominantly high and positive. This was especially true of subjects with formal color training.

Music and Visual Color: A Proposed Correlation

The author tells of events leading up to finding a possible link between musical harmony and visual color based on complementarity. He points out that an equal division of the musical octave into 12 half-steps permits one to recognize chords built on tones occurring at the interval of half an octave or the tritone interval as being complementary to each other. This corresponds to the equal spacing of 12 hues on a color circle in which complementary hues are located diametrically opposite each other. A circularform of the musical octave divided according to the chromatic scale of 12 half- stepsplaces tones serving as rootsfor complementary chords diametrically opposite each other also. There seems to be a parallel between the equal division of the color circle into 3 primaries and 3 secondaries and the equal division of the musical circle into 6 whole steps or the whole-tone scale. In both circles, colors and chords that can be classified as secondaries are complementary to the primaries and vice versa. The near-complements of a color lying on either side of its complement are more subdued in contrast with the color than the complement is. Chords built on tones on either side of a tritone intervalfrom a given tonal center on the musical circle also produce subdued contrast with a chord built on the tonal center. The relationship of the adjacent chords to a chord built on the tonal center is as of sub-dominant to tonic and dominant to tonic, which is the harmonic basis of the diatonic system. I.

Induction of the McCollough effect II: two different mechanisms.

An orientation-specific chromatic aftereffect was observed when a single colored grating was used as an induction stimulus. The magnitude of the aftereffect was compared to that obtained when alternating orthogonal gratings in complementary hues were used as induction stimuli. The two-stimulus condition produced a stronger aftereffect than a single-stimulus condition. This facilitation was also obtained when a colored plain square with no grating was substituted for the second colored grating in the two-stimulus condition. The results suggest that the McCollough effect involves adaptation of two different mechanisms, one which is orientation-specific and one which is not.

Multiple orientation-contingent chromatic after-effects.

McCollough's (1965) original demonstration of an orientation-contingent chromatic after-effect (OCCA) used two orthogonal inducing gratings in complementary colours. Fidell (1970) has shown that inducing gratings whose orientations are separated by less than 90° give progressively smaller OCCAs, becoming ineffective below 20° or so. Stromeyer (1969) found that with only a single inducing grating, orthogonal test fields still appeared tinted in complementary hues, and claimed that these hues could be “neutralized” by rotating the inducing grating by 90°. These results raise the question whether (A) the neural representations of orthogonal orientations are coupled with respect to colour in “opponent” fashion, so that red-horizontal has similar effects to green-vertical; or (B) the representations of orientations separated by some minimum angle are chromatically independent, and can develop substantially independent OCCAs. We report the following results which favour hypothesis (B): (1) With a single coloured inducing grating à la Stromeyer (1969), the measured OCCA at right angles shows no signs of “opponent processing”, if the hue of the test grating is compared against that of a plain field rather than an orthogonal grating. (2) With inducing gratings at several orientations, the resultant OCCA has an angular distribution which is the algebraic sum of those for each grating separately. (3) It is possible to associate the same colour with two orientations at right angles without mutual cancellation. (4) Multiple OCCAs show independent time-courses of decay, and can be induced and retained for at least eight orientations at once.

Chromatic relationships in metacontrast suppression

Total masking of a colored disk in the Werner disk-ring paradigm was found to be a function of the interaction between its color and the color of the ring that followed it. Suppression occurred most frequently when disk and ring hues were identical, least often when complementary hues were paired, and with intermediate frequency when hues were different but noncomplementary. Results were consistent with predictions from simultaneous color contrast, and support integration theories of metacontrast.

Orientation specificity in chromatic adaptation of human “edge-detectors”

The McCollough effect, a pattern-specific complementary hue aftereffect, has usually been demonstrated with horizontal and vertical adapting and test patterns. The present study measured the strength of the effect produced by adapting patterns of various angular separations. The effect decreased with decreasing angular separations until it was minimal at 11 deg of separation. The results are considered to be consistent with an edge-detector interpretation of this aftereffect. With vertical and horizontal adapting patterns, the reddish aftereffect was 17% and the greenish aftereffect 9%of colorimetric purity.

Complementary hues and a schema for color vision.

Complementary hues and a schema for color vision.

Sustained Bidwell Afterimages: Effects of Disc Rotation Speed, Color-Pulse Chromaticity, and Color-Pulse Luminance*†

A sustained complementary hue may be obtained with a rotating black–white disc and pulses of chromatic light. Effects of disc rotation speed and of the chromaticity and luminance of the color pulse are described. The disc. observed at 11 speeds from 10 through 110 cps had a black and white sector. At the sector boundary there was an aperture through which red, yellow, green, blue, or purple light (filters equated for luminous transmittance) was pulsed for 3% of each cycle, followed by the white half cycle. Eleven observers made Munsell matches (total: 4995) to these lights, which were presented at three luminances. Complementary matches occurred 48% of the time, matches similar to the hues of the projected lights—33%, neutral matches—19%. There were systematic hue shifts around two pairs of stable points in the hue circle, as functions of disc rotation speed. The predominance of complementary matches over similar-hue matches varied with color-pulse chromaticity and luminance, and with disc speed.

Complementary hues of after-images.

By a simple adaptation of disk colorimetry the hues of negative after-images of colored surfaces are ascertained to within the equivalent of 1.0 step of Munsell hue. There is good agreement among a number of observers. The complementary pairs thus obtained show differences from those established additively, particularly in the orange-blue region. The relationship between the two sets of complementaries appears to be connected with the change of hue which occurs when colors are desaturated by additive mixture. This change of hue also accounts for the nonuniform spacing of hues which is a necessary feature of color circles based on additive complementary pairs.From the observed changes of hue over a range of colors, lines of constant hue are plotted.