How can I change the saturation of an UIImage?

Question

I have an UIImage and want to shift it\'s saturation about +10%. Are there standard methods or functions that can be used for this?

Answer 1

Swift 5

extension UIImage {
    
    func withSaturationAdjustment(byVal: CGFloat) -> UIImage {
        guard let cgImage = self.cgImage else { return self }
        guard let filter = CIFilter(name: "CIColorControls") else { return self }
        filter.setValue(CIImage(cgImage: cgImage), forKey: kCIInputImageKey)
        filter.setValue(byVal, forKey: kCIInputSaturationKey)
        guard let result = filter.value(forKey: kCIOutputImageKey) as? CIImage else { return self }
        guard let newCgImage = CIContext(options: nil).createCGImage(result, from: result.extent) else { return self }
        return UIImage(cgImage: newCgImage, scale: UIScreen.main.scale, orientation: imageOrientation)
    }

}