The Experts below are selected from a list of 30 Experts worldwide ranked by ideXlab platform
Koichi Ikeda - One of the best experts on this subject based on the ideXlab platform.
-
Comparison of Perceived Colour Differences with Colorimetric Colour Differences in Uniform Colour Spaces and Colour Appearance Model
Journal of Light & Visual Environment, 2004Co-Authors: Masaharu Nakayama, Koichi IkedaAbstract:The visual experiment on perceived colour difference is conducted using 160 colour chips of various Hues arranged on a closed Hue Circle of constant chroma C=6 and of constant value V=6. Correspondence between perceived colour difference and predicted colorimetric colour difference obtained by various colour difference formulae in several colour spaces is examined. The examination is conducted on uniform colour spaces CIELUV, CIELAB, NC-IIIC and L*a*b*-N, colour appearance model CIECAM97s, and colour difference formulae CMC, CIEDE94 and CIEDE2000. Results obtained are as follows: 1) In uniform colour spaces NC-IIIC and L*a*b*-N, predicted colour difference has good correspondence to perceived colour difference. These two uniform colour spaces are implemented with proper non-linear compensation in opponent response process and thus they are significantly superior to other colour spaces in the geometrical uniformity of colour specification. 2) In uniform colour spaces CIELUV and CIELAB, it can be stated that non-uniformity in Hue difference is caused by the fact that Hue and chroma axes are not perpendicular and the fact that Hue and chroma are not independent, both of the above facts originating from the lack of compensation mechanism in opponent response process. 3) The revised colour difference formulae based on the uniform colour space CIELAB, namely CMC, CIEDE94 and CIEDE2000, do not create an improvement to colour difference characteristics compared to the original colour space CIELAB. 4) When designing a uniform colour space or a colour difference formula that ensures accurate colour difference evaluation, it is essential to construct the uniform colour space in which Hue, lightness and chroma axes cross at right angles so that all elements (Hue, lightness and chroma) can be independently evaluated and attached weight by introducing proper non-linear opponent response functions.
Masaharu Nakayama - One of the best experts on this subject based on the ideXlab platform.
-
Comparison of Perceived Colour Differences with Colorimetric Colour Differences in Uniform Colour Spaces and Colour Appearance Model
Journal of Light & Visual Environment, 2004Co-Authors: Masaharu Nakayama, Koichi IkedaAbstract:The visual experiment on perceived colour difference is conducted using 160 colour chips of various Hues arranged on a closed Hue Circle of constant chroma C=6 and of constant value V=6. Correspondence between perceived colour difference and predicted colorimetric colour difference obtained by various colour difference formulae in several colour spaces is examined. The examination is conducted on uniform colour spaces CIELUV, CIELAB, NC-IIIC and L*a*b*-N, colour appearance model CIECAM97s, and colour difference formulae CMC, CIEDE94 and CIEDE2000. Results obtained are as follows: 1) In uniform colour spaces NC-IIIC and L*a*b*-N, predicted colour difference has good correspondence to perceived colour difference. These two uniform colour spaces are implemented with proper non-linear compensation in opponent response process and thus they are significantly superior to other colour spaces in the geometrical uniformity of colour specification. 2) In uniform colour spaces CIELUV and CIELAB, it can be stated that non-uniformity in Hue difference is caused by the fact that Hue and chroma axes are not perpendicular and the fact that Hue and chroma are not independent, both of the above facts originating from the lack of compensation mechanism in opponent response process. 3) The revised colour difference formulae based on the uniform colour space CIELAB, namely CMC, CIEDE94 and CIEDE2000, do not create an improvement to colour difference characteristics compared to the original colour space CIELAB. 4) When designing a uniform colour space or a colour difference formula that ensures accurate colour difference evaluation, it is essential to construct the uniform colour space in which Hue, lightness and chroma axes cross at right angles so that all elements (Hue, lightness and chroma) can be independently evaluated and attached weight by introducing proper non-linear opponent response functions.
C S Mccamy - One of the best experts on this subject based on the ideXlab platform.
-
the primary Hue Circle
Color Research and Application, 1993Co-Authors: C S MccamyAbstract:Munsell started to base his color-order system on measured physical quantities, but it came to represent the order of colors us they ure perceived. The Hue Circle represents fundamental facts about color vision. The Munsell Hue Circle has anomalous placement of blue and the use ($five principal Hues does not relate to color vision nor applied color science. A reoriented Hue Circle, labeled with the additive and subtractive primariesblue,green, red, yellow, magentu, and cyan-but retaining the existing Munsell Hue spacing and sectors is proposed.The primury Hue Circle relates to vision and color-reproduction processes, so it should exert a unifying influence on color .science. 0 1993 John Wi1ey . & Sons. Inc..
Rolf G Kuehni - One of the best experts on this subject based on the ideXlab platform.
-
Hue uniformity and the cielab space and color difference formula
Color Research and Application, 1998Co-Authors: Rolf G KuehniAbstract:The Hue uniformity of the CIELAB system is investigated using a Hue Circle of Munsell colors at value 6 and chroma 14 and experimentally determined Hue coefficient data. CIELAB Hue differences for equal Munsell Hue increments are found to vary up to nearly a factor 4, and Hue coefficients differ from the experimentally determined ones by up to 40% at certain wavelengths. Dominant wavelengths assigned by the CIELAB system to individual Munsell Hues are found to vary up to 35 nm from those of the Munsell Renotations. Four other color space systems are compared with widely differing but comparable results. The CIE 2° color-matching functions are adapted to result in a set of opponent-color functions accurately representing the Munsell Hue and Chroma data. A call is made for the experimental determination of the “standard Hue observer” as a step toward an improved color space/color-difference formula. © 1998 John Wiley & Sons, Inc. Col Res Appl, 23, 314–322, 1998
Shihmiao Huang - One of the best experts on this subject based on the ideXlab platform.
-
a study of Hue identification in the Hue Circle of the hsb color space
Perceptual and Motor Skills, 2005Co-Authors: Shihmiao HuangAbstract:The purpose of the present research was to explore the relationship between the sensory difference in Hues in the Hue Circle of the HSB color space and their included angles in identification tasks. In the experiment, the two colors were presented separately, and the test subjects judged whether the two colors were the same or different. Five Hues, called Standard Stimulus Hues and the most saturated colors in the Hue Circle of the HSB color space, were discussed. These are Hue 0 degrees, Hue 72 degrees, Hue 216 degrees, and Hue 288 degrees in the HSB color space. The Just Identifiable Angle refers to the included angle between a specific standard Hue and the Hue which cannot be identified separately and which is the furthest from the standard Hue in the Hue Circle of the HSB color space. Analysis gave a significant main effect of standard Hue. The Just Identifiable Angles for Hue 72 degrees and Hue 288 degrees did not differ significantly, but their Just Identifiable Angles were discernibly lower than those for the other three Hues. The Just Identifiable Angle of Hue 144 degrees was significantly lower than those for Hue 0 degrees and Hue 216 degrees. In addition, the Just Identifiable Angle for Hue 0 degrees was noticeably larger than the one for Hue 216 degrees, so the final outcome might show that the Just Identifiable angles of the standard Hues are not equal.