iOS 7 Core Image QR Code generation too blur

Question

here\'s my code for generating QRCode image

+ (UIImage *)generateQRCodeWithString:(NSString *)string {
    NSData *stringData = [string dataUsingEncoding:NSU         


        

Answer 1

I had to adapt @cromanelli's answer to achieve perfect sharpness :

func convertTextToQRCode(text: String, withSize size: CGSize) -> UIImage {

    let data = text.dataUsingEncoding(NSISOLatin1StringEncoding, allowLossyConversion: false)

    let filter = CIFilter(name: "CIQRCodeGenerator")!

    filter.setValue(data, forKey: "inputMessage")
    filter.setValue("L", forKey: "inputCorrectionLevel")

    var qrcodeCIImage = filter.outputImage!

    let cgImage = CIContext(options:nil).createCGImage(qrcodeCIImage, fromRect: qrcodeCIImage.extent)
    UIGraphicsBeginImageContext(CGSizeMake(size.width * UIScreen.mainScreen().scale, size.height * UIScreen.mainScreen().scale))
    let context = UIGraphicsGetCurrentContext()
    CGContextSetInterpolationQuality(context, .None)
    CGContextDrawImage(context, CGContextGetClipBoundingBox(context), cgImage)
    let preImage = UIGraphicsGetImageFromCurrentImageContext()
    UIGraphicsEndImageContext()

    let qrCodeImage = UIImage(CGImage: preImage.CGImage!, scale: 1.0/UIScreen.mainScreen().scale, orientation: .DownMirrored)

    return qrCodeImage
}