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juliengdt/gist:aa0554bc32d1f34c1f247e1b140115f1

Created May 24, 2019 13:29
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  1. juliengdt created this gist May 24, 2019.
    28 changes: 28 additions & 0 deletions gistfile1.txt
    View file
    Original file line number Diff line number Diff line change
    @@ -0,0 +1,28 @@
    extension CGImage {
    var brightness: Double {
    get {
    let imageData = self.dataProvider?.data
    let ptr = CFDataGetBytePtr(imageData)
    var x = 0
    var result: Double = 0
    for _ in 0..<self.height {
    for _ in 0..<self.width {
    let r = ptr![0]
    let g = ptr![1]
    let b = ptr![2]
    result += (0.299 * Double(r) + 0.587 * Double(g) + 0.114 * Double(b))
    x += 1
    }
    }
    let bright = result / Double (x)
    return bright
    }
    }
    }
    extension UIImage {
    var brightness: Double {
    get {
    return (self.cgImage?.brightness)!
    }
    }
    }