How to get a quality barcode image from string in ios, swift - ios

Question

I'm generating an image with barcode using its string like below.
class BarCode {
class func fromString(string : String) -> UIImage? {
let data = string.dataUsingEncoding(NSASCIIStringEncoding)
let filter = CIFilter(name: "CICode128BarcodeGenerator")
filter!.setValue(data, forKey: "inputMessage")
return UIImage(CIImage: filter!.outputImage!)
}
}
so this generates a accurate image. but the quality is low. how can I increase the quality of the image.(I cant increase the size of the image, if I do so it looks liked blured)

Answer 1

When the CIImage is converted to a UIImage it does so with a fixed size that is determined by the CIImage, if you subsequently try to scale this image up, say by assigning it to a UIImageView, then you will get the typical pixellation associated with scaling up a bitmap.
Transform the image before assigning it to the UIImage
if let barImage = filter.outputImage {
let transform = CGAffineTransformMakeScale(5.0, 5.0)
let scaled = barImage.imageByApplyingTransform(transform)
return(UIImage(CIImage: scaled))
}

Answer 2

Try transform to make it bigger
let transform = CGAffineTransform(scaleX: 3, y: 3)
if let output = filter.outputImage?.applying(transform) {
return UIImage(ciImage: output)
}

Answer 3

my two cents for OSX :)
func barCodeFromString(string : String) -> NSImage? {
let data = string.data(using: .ascii)
guard let filter = CIFilter(name: "CICode128BarcodeGenerator") else{
return nil
}
filter.setValue(data, forKey: "inputMessage")
guard let ciImage : CIImage = filter.outputImage else{
return nil
}
let transform = CGAffineTransform(scaleX: 5.0, y: 5.0)
let scaled = ciImage.transformed(by: transform)
let rep = NSCIImageRep(ciImage: scaled)
let nsImage = NSImage(size: rep.size)
nsImage.addRepresentation(rep)
return nsImage
}