如何从 ios、swift 中的字符串获取高质量条码图像

Question

我正在使用如下所示的字符串生成带条形码的图像。

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!)

    }
}

所以这会生成准确的图像。但质量很低。我怎样才能提高图像的质量。（我不能增加图像的大小，如果我这样做它看起来像模糊）

Answer 1

尝试transform让它变大

    let transform = CGAffineTransform(scaleX: 3, y: 3)

    if let output = filter.outputImage?.applying(transform) {
        return UIImage(ciImage: output)
    }

Answer 2

当 CIImage 转换为 UIImage 时，它会使用由 CIImage 确定的固定大小，如果您随后尝试放大此图像，比如说通过将其分配给 UIImageView，您将获得与放大位图相关的典型像素化。

在将图像分配给 UIImage 之前转换图像

if let barImage = filter.outputImage {
    let transform = CGAffineTransformMakeScale(5.0, 5.0)
    let scaled = barImage.imageByApplyingTransform(transform)
    return(UIImage(CIImage: scaled))
}

Answer 3

我的两分钱 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
}

如何从 ios、swift 中的字符串获取高质量条码图像

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

barcode

uiimage

ios

swift