Class: Color::YIQ

Inherits:
Data
  • Object
show all
Includes:
Color
Defined in:
lib/color/yiq.rb,
lib/color.rb

Overview

A Color object representing YIQ (NTSC) color encoding, where Y is the luma (brightness) value, and I (orange-blue) and Q (purple-green) are chrominance.

All values are clamped between 0 and 1 inclusive.

More more details, see [YIQ].

[wikiyiq]: en.wikipedia.org/wiki/YIQ

YIQ colors are immutable Data class instances. Array deconstruction is ‘[y, i, q]` and hash deconstruction is `i:, q:` (see #y, #i, #q).

YIQ is only partially implemented: other Color objects can only be converted to YIQ, but it has few conversion functions for converting from YIQ.

Constant Summary

Constants included from Color

EPSILON, TOLERANCE, VERSION

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Methods included from Color

#==, #components, #css_value, #map, #map_with, normalize, #scale, translate_range, #zip

Constructor Details

#initialize(y:, i:, q:) ⇒ YIQ

Creates a YIQ color object from fractional values 0 .. 1.

“‘ruby Color::YIQ.from_fraction(0.3, 0.2, 0.1) # => YIQ [30% 20% 10%] Color::YIQ.new(0.3, 0.2, 0.1) # => YIQ [30% 20% 10%] Color::YIQ[y: 0.3, i: 0.2, q: 0.1] # => YIQ [30% 20% 10%] “`



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# File 'lib/color/yiq.rb', line 71

def initialize(y:, i:, q:) # :nodoc:
  super(y: normalize(y), i: normalize(i), q: normalize(q))
end

Instance Attribute Details

#i ⇒ Object (readonly)

Returns the value of attribute i

Returns:

  • (Object) —

    the current value of i



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

def i
  @i
end

#q ⇒ Object (readonly)

Returns the value of attribute q

Returns:

  • (Object) —

    the current value of q



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

def q
  @q
end

#y ⇒ Object (readonly) Also known as: brightness

Returns the value of attribute y

Returns:

  • (Object) —

    the current value of y



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

def y
  @y
end

Class Method Details

.from_percentage(*args, **kwargs) ⇒ Object Also known as: from_values

Creates a YIQ color object from percentage values 0 .. 1.

“‘ruby Color::YIQ.from_percentage(30, 20, 10) # => YIQ [30% 20% 10%] Color::YIQ.from_percentage(y: 30, i: 20, q: 10) # => YIQ [30% 20% 10%] Color::YIQ.from_values(30, 20, 10) # => YIQ [30% 20% 10%] Color::YIQ.from_values(y: 30, i: 20, q: 10) # => YIQ [30% 20% 10%] “`



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

def self.from_percentage(*args, **kwargs)
  y, i, q =
    case [args, kwargs]
    in [[_, _, _], {}]
      args
    in [[], {y:, i:, q:}]
      [y, i, q]
    else
      new(*args, **kwargs)
    end

  new(y: y / 100.0, i: i / 100.0, q: q / 100.0)
end

Instance Method Details

#coerce(other) ⇒ Object

Coerces the other Color object into YIQ.



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# File 'lib/color/yiq.rb', line 77

def coerce(other) = other.to_yiq

#deconstruct_keys(_keys) ⇒ Object

:nodoc:



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# File 'lib/color/yiq.rb', line 106

def deconstruct_keys(_keys) = {y:, i:, q:} # :nodoc:

#inspect ⇒ Object

:nodoc:



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# File 'lib/color/yiq.rb', line 89

def inspect = "YIQ [%.2f%% %.2f%% %.2f%%]" % [y * 100, i * 100, q * 100] # :nodoc:

#pretty_print(q) ⇒ Object

:nodoc:



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# File 'lib/color/yiq.rb', line 91

def pretty_print(q) # :nodoc:
  q.text "YIQ"
  q.breakable
  q.group 2, "[", "]" do
    q.text "%.2f%%" % y
    q.fill_breakable
    q.text "%.2f%%" % i
    q.fill_breakable
    q.text "%.2f%%" % q
  end
end

#to_grayscale ⇒ Object

Convert YIQ to Color::Grayscale using the luma (#y) value.



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# File 'lib/color/yiq.rb', line 84

def to_grayscale = Color::Grayscale.from_fraction(y)

#to_yiq ⇒ Object 



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# File 'lib/color/yiq.rb', line 80

def to_yiq = self