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Hue is one of the main properties (called color appearance parameters) of a color, defined technically (in the CIECAM02 model), as "the degree to which a stimulus can be described as similar to or different from stimuli that are described as red, green, blue, and yellow"〔Mark Fairchild, "Color Appearance Models: CIECAM02 and Beyond". Tutorial slides for IS&T/SID 12th Color Imaging Conference.〕 (the unique hues). Orange and violet (purple) are the other hues, for a total of six, as in the rainbow: red, orange, yellow, green, blue, violet. The other color appearance parameters are colorfulness, chroma, saturation, lightness, and brightness. Usually, colors with the same hue are distinguished with adjectives referring to their lightness and/or colorfulness, such as with "light blue", "pastel blue", "vivid blue". Exceptions include brown, which is a dark orange,〔C J Bartleson, "Brown". ''Color Research and Application,'' 1 : 4, p 181-191 (1976).〕 and pink, a light red with reduced chroma. In painting color theory, a hue refers to a ''pure'' color—one without tint or shade (added white or black pigment, respectively). A hue is an element of the color wheel. Hues are first processed in the brain in areas in the extended V4 called globs. == Computing hue == In opponent color spaces in which two of the axes are perceptually orthogonal to lightness, such as the CIE 1976 (''L'' *, ''a'' *, ''b'' *) (CIELAB) and 1976 (''L'' *, ''u'' *, ''v'' *) (CIELUV) color spaces, hue may be computed together with chroma by converting these coordinates from rectangular form to polar form. Hue is the angular component of the polar representation, while chroma is the radial component. Specifically, in CIELAB〔''Colorimetry,'' second edition: CIE Publication 15.2. Vienna: Bureau Central of the CIE, 1986.〕 : while, analogously, in CIELUV〔 : where, atan2 is a two-argument inverse tangent. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「hue」の詳細全文を読む スポンサード リンク
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