Class: Abachrome::Converters::YiqToSrgb

Inherits:
Object
  • Object
show all
Defined in:
lib/abachrome/converters/yiq_to_srgb.rb

Class Method Summary collapse

Class Method Details

.convert(yiq_color) ⇒ Abachrome::Color

Converts a color from YIQ color space to sRGB color space. This method applies the inverse NTSC transformation matrix.

with the same alpha value as the input color

Parameters:

Returns:



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# File 'lib/abachrome/converters/yiq_to_srgb.rb', line 28

def self.convert(yiq_color)
  y, i, q = yiq_color.coordinates.map { |c| AbcDecimal(c) }

  # Inverse NTSC YIQ to RGB transformation matrix
  # R = Y + 0.956I + 0.619Q
  # G = Y - 0.272I - 0.647Q
  # B = Y - 1.106I + 1.703Q
  r = y + (AD("0.9563") * i) + (AD("0.6210") * q)
  g = y - (AD("0.2721") * i) - (AD("0.6474") * q)
  b = y - (AD("1.1070") * i) + (AD("1.7046") * q)

  Color.new(
    ColorSpace.find(:srgb),
    [r, g, b],
    yiq_color.alpha
  )
end