NSImage to CIImage and NSImage from CIImage OSX IOS Swift 4

extensions.swift

import Cocoa

extension NSImage {
    var ciimage: CIImage? {
        guard let tiffData = self.tiffRepresentation,
            let bitmap = NSBitmapImageRep(data: tiffData) else {
            return nil
        }
        return CIImage(bitmapImageRep: bitmap)
    }
}
extension CIImage {
    var nsImage: NSImage {
        let rep = NSCIImageRep(ciImage: self)
        let nsImage = NSImage(size: rep.size)
        nsImage.addRepresentation(rep)
        return nsImage
    }
}