Class: AutoColors::Color

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

Overview

http://cs.haifa.ac.il/hagit/courses/ist/Lectures/Demos/ColorApplet2/t_convert.html http://en.wikipedia.org/wiki/Lab_color_space

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(lab, rgb = nil) ⇒ Color

Returns a new instance of Color.



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# File 'lib/autocolors/color.rb', line 12

def initialize(lab,rgb=nil)
  if rgb.nil?
    @cl,@ca,@cb = lab.map{|v| v.to_f}
    @lab_dirty = true
    @rgb_dirty = false
  else
    @r,@g,@b = rgb.map{|v| v.to_f}
    @lab_dirty = false
    @rgb_dirty = true
  end
end

Instance Attribute Details

#rgb_approx ⇒ Object (readonly)

Returns the value of attribute rgb_approx.



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# File 'lib/autocolors/color.rb', line 10

def rgb_approx
  @rgb_approx
end

Instance Method Details

#-(c) ⇒ Object 



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# File 'lib/autocolors/color.rb', line 94

def -(c)
  if c.is_a?(Color)
    # Euclidean distance in 3 dimensions, but emphasize brightness a bit
    # more than the color (which is more how the human eye works)
    Math.sqrt((cl*2.5 - c.cl*2.5)**2 + (ca - c.ca)**2 + (cb - c.cb)**2)
  end
end

#b ⇒ Object 



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# File 'lib/autocolors/color.rb', line 46

def b;      lab_propagate if @lab_dirty; @b               end

#b=(v) ⇒ Object 



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# File 'lib/autocolors/color.rb', line 50

def b=(v)   @rgb_dirty=true; @b=v.to_f                    end

#ca ⇒ Object 



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# File 'lib/autocolors/color.rb', line 35

def ca;     rgb_propagate if @rgb_dirty; @ca              end

#ca=(v) ⇒ Object 



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# File 'lib/autocolors/color.rb', line 39

def ca=(v)  @lab_dirty=true; @ca=v.to_f                   end

#cb ⇒ Object 



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# File 'lib/autocolors/color.rb', line 36

def cb;     rgb_propagate if @rgb_dirty; @cb              end

#cb=(v) ⇒ Object 



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# File 'lib/autocolors/color.rb', line 40

def cb=(v)  @lab_dirty=true; @cb=v.to_f                   end

#chroma ⇒ Object 



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# File 'lib/autocolors/color.rb', line 54

def chroma; Math::sqrt((ca * ca) + (cb * cb))             end

#chroma=(v) ⇒ Object 



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# File 'lib/autocolors/color.rb', line 83

def chroma=(v)
  q = Math.atan2(ca, cb)
  v = v.to_f
  self.ca = Math::sin(q) * v
  self.cb = Math::cos(q) * v
end

#cl ⇒ Object 



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# File 'lib/autocolors/color.rb', line 34

def cl;     rgb_propagate if @rgb_dirty; @cl              end

#cl=(v) ⇒ Object 



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# File 'lib/autocolors/color.rb', line 38

def cl=(v)  @lab_dirty=true; @cl=v.to_f                   end

#g ⇒ Object 



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# File 'lib/autocolors/color.rb', line 45

def g;      lab_propagate if @lab_dirty; @g               end

#g=(v) ⇒ Object 



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# File 'lib/autocolors/color.rb', line 49

def g=(v)   @rgb_dirty=true; @g=v.to_f                    end

#hue ⇒ Object

Hue & chroma



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# File 'lib/autocolors/color.rb', line 53

def hue;    rad2turns(Math.atan2(ca, cb))                 end

#hue=(v) ⇒ Object 



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# File 'lib/autocolors/color.rb', line 76

def hue=(v)
  r = turns2rad(v.to_f)
  c = chroma
  self.ca = Math::sin(r) * c
  self.cb = Math::cos(r) * c
end

#hue_index=(v) ⇒ Object 



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# File 'lib/autocolors/color.rb', line 56

def hue_index=(v)
  self.hue = [
    0.0,     # 0  | Blue
    0.15,    # 1  | Cyan
    0.225,   # 2  | Teal
    0.33,    # 3  | Green
    0.4,     # 4  | Forest green
    0.45,    # 5  | Puke green
    0.5,     # 6  | Yellow
    0.565,   # 7  | Orange
    0.625,   # 8  | Orange-red
    0.6575,  # 9  | Red
    0.75,    # 10 | Magenta
    0.825,   # 11 | Fuchsia
    0.8875,  # 12 | Pink
    0.925,   # 13 | Violet
    0.95     # 14 | Indigo
  ][v.to_i]
end

#lab ⇒ Object

CIELAB colorspace



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# File 'lib/autocolors/color.rb', line 33

def lab;    rgb_propagate if @rgb_dirty; [@cl,@ca,@cb]    end

#lab=(v) ⇒ Object 



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# File 'lib/autocolors/color.rb', line 37

def lab=(v) @lab_dirty=true; @cl,@ca,@cb=v.map{|a|a.to_f} end

#lab_propagate ⇒ Object (protected) 



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# File 'lib/autocolors/color.rb', line 113

def lab_propagate
  p = (@cl + 16.0) / 116.0
  @x = (p + @ca / 500.0) ** 3.0
  @y = p ** 3.0
  @z = (p - @cb / 200.0) ** 3.0
  @lr,@lg,@lb = (XYZ2LRGB*Matrix[[@x],[@y],[@z]]).to_a.flatten
  @rgb_approx = false
  @r,@g,@b = [@lr,@lg,@lb].map{|c|lrgbc_to_rgbc(c)}
  @lab_dirty = false
end

#labf(t) ⇒ Object (protected) 



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# File 'lib/autocolors/color.rb', line 124

def labf(t)
  t > 0.008856 ? t**(1.0/3.0) : 7.787 * t + (16.0/116.0)
end

#lb ⇒ Object 



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

def lb; rgb_propagate if @rgb_dirty; lab_propagate if @lab_dirty; @lb end

#lg ⇒ Object 



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# File 'lib/autocolors/color.rb', line 26

def lg; rgb_propagate if @rgb_dirty; lab_propagate if @lab_dirty; @lg end

#lr ⇒ Object

Intermediate spaces



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# File 'lib/autocolors/color.rb', line 25

def lr; rgb_propagate if @rgb_dirty; lab_propagate if @lab_dirty; @lr end

#lrgbc_to_rgbc(c) ⇒ Object (protected) 



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# File 'lib/autocolors/color.rb', line 135

def lrgbc_to_rgbc(c)
  if c <= 0.0031308 then v = (12.92 * c * 255.0).round
  else v = ((1.055 * (c ** (1.0/2.4)) - 0.055) * 255.0).round end
  if v < 0 then @rgb_approx = true; 0
  elsif v > 255 then @rgb_approx = true; 255
  else v end
end

#r ⇒ Object 



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# File 'lib/autocolors/color.rb', line 44

def r;      lab_propagate if @lab_dirty; @r               end

#r=(v) ⇒ Object 



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# File 'lib/autocolors/color.rb', line 48

def r=(v)   @rgb_dirty=true; @r=v.to_f                    end

#rad2turns(r) ⇒ Object (protected) 



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# File 'lib/autocolors/color.rb', line 143

def rad2turns(r) (r + Math::PI) / (2.0 * Math::PI) end

#rgb ⇒ Object

RGB colorspace



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# File 'lib/autocolors/color.rb', line 43

def rgb;    lab_propagate if @lab_dirty; [@r,@g,@b]       end

#rgb=(v) ⇒ Object 



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# File 'lib/autocolors/color.rb', line 47

def rgb=(v) @rgb_dirty=true; @r,@g,@b=v.map{|a|a.to_f}    end

#rgb_propagate ⇒ Object (protected) 



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# File 'lib/autocolors/color.rb', line 104

def rgb_propagate
  @lr,@lg,@lb = [@r,@g,@b].map{|c|rgbc_to_lrgbc(c)}
  @x,@y,@z = (LRGB2XYZ*Matrix[[@lr],[@lg],[@lb]]).to_a.flatten
  @cl = (@y > 0.008856) ? 116.0*(@y ** (1.0/3.0)) - 16.0 : 903.3 * @y
  @ca = 500.0 * (labf(@x) - labf(@y))
  @cb = 200.0 * (labf(@y) - labf(@z))
  @rgb_dirty = false
end

#rgbc_to_lrgbc(c) ⇒ Object (protected)

http://en.wikipedia.org/wiki/SRGB_color_space



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# File 'lib/autocolors/color.rb', line 129

def rgbc_to_lrgbc(c)
  cf = c.to_f / 255.0
  if cf <= 0.04045 then cf / 12.92
  else ((cf + 0.055) / 1.055) ** 2.4 end
end

#s_cterm ⇒ Object 



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# File 'lib/autocolors/color.rb', line 192

def s_cterm
  'NONE'
end

#s_high ⇒ Object 



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# File 'lib/autocolors/color.rb', line 196

def s_high
  'NONE'
end

#s_lcterm ⇒ Object 



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# File 'lib/autocolors/color.rb', line 188

def s_lcterm
  'NONE'
end

#s_term ⇒ Object 



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# File 'lib/autocolors/color.rb', line 184

def s_term
  'NONE'
end

#to_16 ⇒ Object 



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# File 'lib/autocolors/color.rb', line 180

def to_16
  CUBE256[0..15].each_with_index.map{|c,i| [i,c-self]}.sort_by{|i,diff| diff}.first[0]
end

#to_256 ⇒ Object 



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# File 'lib/autocolors/color.rb', line 175

def to_256
  CUBE256.each_with_index.map{|c,i| [i,c-self]}.sort_by{|i,diff| diff}.first[0]
  #CUBE256.sort_by{|c| c - self}.first
end

#to_s ⇒ Object 



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# File 'lib/autocolors/color.rb', line 90

def to_s
  '#' + rgb.map{|v|v.to_s(16).rjust(2,'0')}.join('')
end

#turns2rad(t) ⇒ Object (protected) 



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# File 'lib/autocolors/color.rb', line 144

def turns2rad(t) (t * 2.0 * Math::PI) - Math::PI end

#x ⇒ Object 



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# File 'lib/autocolors/color.rb', line 28

def x; rgb_propagate if @rgb_dirty; lab_propagate if @lab_dirty; @x end

#y ⇒ Object 



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# File 'lib/autocolors/color.rb', line 29

def y; rgb_propagate if @rgb_dirty; lab_propagate if @lab_dirty; @y end

#z ⇒ Object 



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# File 'lib/autocolors/color.rb', line 30

def z; rgb_propagate if @rgb_dirty; lab_propagate if @lab_dirty; @z end