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nagelflorian/strongestContrast.swift

Created March 11, 2015 21:54
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Returns black or white based on relative luminance
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strongestContrast.swift
func strongestContrast(color: UIColor) -> UIColor {
let colorRef: CGColorRef = color.CGColor
let components = CGColorGetComponents(colorRef)
let relativeLuminance = 1 - (0.2126 * components[0] + 0.7152 * components[1] + 0.0722 * components[2])
if (relativeLuminance >= 0.5) {
return UIColor.whiteColor()
} else {
return UIColor.blackColor()
}
}
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More infos on Relative Luminance here.

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