Class: ColorDecomposition::Color

Inherits:
Object
  • Object
show all
Defined in:
lib/color_decomposition/color/color.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(rgb) ⇒ Color

Returns a new instance of Color.



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# File 'lib/color_decomposition/color/color.rb', line 7

def initialize(rgb)
  @rgb = rgb
end

Instance Attribute Details

#rgb ⇒ Object (readonly)

Returns the value of attribute rgb.



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# File 'lib/color_decomposition/color/color.rb', line 5

def rgb
  @rgb
end

Instance Method Details

#lab ⇒ Object 



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# File 'lib/color_decomposition/color/color.rb', line 27

def lab
  @lab ||= begin
    # CIEXYZ white point values (D65)
    x = lab_channel(xyz[:x] / 95.047)
    y = lab_channel(xyz[:y] / 100.000)
    z = lab_channel(xyz[:z] / 108.883)

    l = 116 * y - 16
    a = 500 * (x - y)
    b = 200 * (y - z)
    { l: l.clamp(0, 100), a: a, b: b }
  end
end

#xyz ⇒ Object 



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# File 'lib/color_decomposition/color/color.rb', line 11

def xyz
  @xyz ||= begin
    r = xyz_channel(@rgb[:r] / 255.0)
    g = xyz_channel(@rgb[:g] / 255.0)
    b = xyz_channel(@rgb[:b] / 255.0)

    # sRGB D65 illuminant and 2 degrees observer values
    s = Matrix[[0.4124, 0.3576, 0.1805],
               [0.2126, 0.7152, 0.0722],
               [0.0193, 0.1192, 0.9505]]

    xyz = s * Matrix[[r], [g], [b]] * 100
    { x: xyz[0, 0], y: xyz[1, 0], z: xyz[2, 0] }
  end
end