Question

UIImageJPEGRpresentation（）的功能可以将JPEG的UIImage转换为NSData，但它是否无损？我想从系统相册中选择一个图像并将其转换为NSData，有一些方法可以实现这个目标吗？先谢谢了！

Answer 1

要从设备中挑选图片，您必须使用UIImagePickerController

let picker = UIImagePickerController()

将以下内容添加到viewDidLoad()

picker.delegate = self
picker.allowsEditing = false
picker.sourceType = .photoLibrary    //You can also go with .camera

要打开选择器视图，请添加此

 self.present(picker, animated: true, completion: nil)

为选择器视图添加委托方法以获取拾取的图像

func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any]) {
    let chosenImage = info[UIImagePickerControllerOriginalImage] as! UIImage
    // Convert image to NSData
    let data = UIImagePNGRepresentation(image) as NSData?   //Your image as NSData
    dismiss(animated: true, completion: nil)
}

func imagePickerControllerDidCancel(_ picker: UIImagePickerController) {
    dismiss(animated: true, completion: nil)
}

<强> *注意不要忘记将Privacy - Photo Library Usage Description添加到您的Info.plist文件和UIImagePickerControllerDelegate, UINavigationControllerDelegate

Answer 2

虽然UIImageJPEGRpresentation（）将质量值作为第二个参数，但它总是有损的！

改为使用UIImagePNGRepresentation（）。

如何转换JPEG＆＃39; UIImage无损NSData？

2 个答案: