class Color::XYZ

Public Class Methods

cgats_fields() click to toggle source
# File lib/quadtone/color/xyz.rb, line 14
def self.cgats_fields
  %w{XYZ_X XYZ_Y XYZ_Z}
end
component_names() click to toggle source
# File lib/quadtone/color/xyz.rb, line 10
def self.component_names
  [:x, :y, :z]
end
standard_reference() click to toggle source

Observer= 2°, Illuminant= D65

# File lib/quadtone/color/xyz.rb, line 6
def self.standard_reference
  @@reference ||= new([95.047, 100.000, 108.883])
end

Public Instance Methods

to_cgats() click to toggle source
# File lib/quadtone/color/xyz.rb, line 70
def to_cgats
  {
    'XYZ_X' => x,
    'XYZ_Y' => y,
    'XYZ_Z' => z,
  }
end
to_lab() click to toggle source
# File lib/quadtone/color/xyz.rb, line 30
def to_lab
  # http://www.easyrgb.com/index.php?X=MATH&H=07#text7

  ref = self.class.standard_reference

  x = self.x / ref.x
  y = self.y / ref.y
  z = self.z / ref.z

  x, y, z = [x, y, z].map do |n|
    if n > 0.008856
      n ** (1.0 / 3)
    else
      (7.787 * n) + (16 / 116)
    end
  end

  l = (116 * y) - 16
  a = 500 * (x - y)
  b = 200 * (y - z)

  Color::Lab.new([l, a, b])
end
to_rgb() click to toggle source
# File lib/quadtone/color/xyz.rb, line 54
def to_rgb
  rgb = [
    (x *  3.2406) + (y * -1.5372) + (z * -0.4986),
    (x * -0.9689) + (y *  1.8758) + (z *  0.0415),
    (x *  0.0557) + (y * -0.2040) + (z *  1.0570),
  ]
  rgb = rgb.map do |n|
    if n > 0.0031308
      1.055 * (n ** (1 / 2.4)) - 0.055
    else
      12.92 * rgb[0]
    end
  end
  Color::RGB.new(rgb)
end
x() click to toggle source
# File lib/quadtone/color/xyz.rb, line 18
def x
  @components[0]
end
y() click to toggle source
# File lib/quadtone/color/xyz.rb, line 22
def y
  @components[1]
end
z() click to toggle source
# File lib/quadtone/color/xyz.rb, line 26
def z
  @components[2]
end