Unable to convert CIImage to UIImage in Swift 3.0
func convert(cmage:CIImage) -> UIImage{ let context:CIContext = CIContext.init(options: nil) let cgImage:CGImage = context.createCGImage(cmage, from: cmage.extent)! let image:UIImage = UIImage.init(cgImage: cgImage) return image}Use this function to convert CIImage to UIImage . It works .
My final code
func generateQRCode(from string: String) -> UIImage? { let data = string.data(using: String.Encoding.ascii) if let filter = CIFilter(name: "CIQRCodeGenerator") { filter.setValue(data, forKey: "inputMessage") let transform = CGAffineTransform(scaleX: 3, y: 3) if let output = filter.outputImage?.transformed(by: transform) { let context:CIContext = CIContext.init(options: nil) let cgImage:CGImage = context.createCGImage(output, from: output.extent)! let image:UIImage = UIImage.init(cgImage: cgImage) return image } } return nil }