Calculating Luminance

code.js

function calculateLuminance(color) {
  const normalizedColor = color.map(channel => channel / 255)
  const gammaCorrectedRGB = normalizedColor.map(channel =>
    channel <= 0.03928
      ? channel / 12.92
      : Math.pow((channel + 0.055) / 1.055, 2.4)
  )
  const luminance =
    gammaCorrectedRGB[0] * 0.2126 +
    gammaCorrectedRGB[1] * 0.7152 +
    gammaCorrectedRGB[2] * 0.0722
  return luminance
}