iOS Swift 3 图像向左旋转90度

Question

我的应用程序具有从相机拍摄照片并将其上传到服务器的功能。我的问题是，当我从服务器获取响应时，图像会向左旋转90度。以下是我尝试过的代码：

func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any])
{
    self.PickerFrom = self.PickerFrom2
    if let pickedImage = info[UIImagePickerControllerOriginalImage] as? UIImage
    {
       self.AttachmentImageView.image = pickedImage
    }
    dismiss(animated: true, completion: nil)
    uploadGalleryImage(image: self.AttachmentImageView.image!)
}

func uploadGalleryImage( image:UIImage)
{
    let imageData: NSData = UIImagePNGRepresentation(image)! as NSData
    let base64String = imageData.base64EncodedString(options: NSData.Base64EncodingOptions(rawValue: 0))
    self.AttachedDocumentURL = "data:image/png;base64,\(base64String)"
}

AttachedDocumentURL 包含捕获图像的 base64 字符串。

- Kavin Kumar Arumugam

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图片在服务器上是如何保存的，是以90度存储还是正常存储？ - Anbu.Karthik

当您使用手机拍照时，该图像本身具有方向属性。因此，请检查并根据该方向旋转并发送到服务器。网络上有很多代码可用，或者您可以自己编写。 - Ammaiappan

你可以在这里检查我的答案 https://stackoverflow.com/questions/45157225/want-fixed-orientation-but-the-uiimage-autoratate/45157920#45157920 - luckyShubhra

Answer 1

在上传到服务器之前，请尝试使用此方法（重置图像方向）

func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any])
{
    self.PickerFrom = self.PickerFrom2
    if let pickedImage = info[UIImagePickerControllerOriginalImage] as? UIImage
    {
       self.AttachmentImageView.image = pickedImage
    }
    dismiss(animated: true, completion: nil)

    if let updatedImage = self.AttachmentImageView.image?.updateImageOrientionUpSide() {
      uploadGalleryImage(image: updatedImage)
    } else {
      uploadGalleryImage(image: self.AttachmentImageView.image!)
    }

}

func uploadGalleryImage( image:UIImage)
{
    let imageData: NSData = UIImagePNGRepresentation(image)! as NSData
    let base64String = imageData.base64EncodedString(options: NSData.Base64EncodingOptions(rawValue: 0))
    self.AttachedDocumentURL = "data:image/png;base64,\(base64String)"
}

// Image extension
extension UIImage {

    func updateImageOrientionUpSide() -> UIImage? {
        if self.imageOrientation == .up {
            return self
        }

        UIGraphicsBeginImageContextWithOptions(self.size, false, self.scale)
        self.draw(in: CGRect(x: 0, y: 0, width: self.size.width, height: self.size.height))
        if let normalizedImage:UIImage = UIGraphicsGetImageFromCurrentImageContext() {
            UIGraphicsEndImageContext()
            return normalizedImage
        }
        UIGraphicsEndImageContext()
        return nil
    }
}

- Krunal

Answer 2

使用这个常用函数可以修正任何图片的上下方向。

extension UIImage {

    func fixImageOrientation() -> UIImage? {


        if (self.imageOrientation == .up) {
            return self
        }

        var transform: CGAffineTransform = CGAffineTransform.identity


        if ( self.imageOrientation == .left || self.imageOrientation == .leftMirrored ) {
            transform = transform.translatedBy(x: self.size.width, y: 0)
            transform = transform.rotated(by: CGFloat(Double.pi / 2.0))
        } else if ( self.imageOrientation == .right || self.imageOrientation == .rightMirrored ) {
            transform = transform.translatedBy(x: 0, y: self.size.height);
            transform = transform.rotated(by: CGFloat(-Double.pi / 2.0));
        } else if ( self.imageOrientation == .down || self.imageOrientation == .downMirrored ) {
            transform = transform.translatedBy(x: self.size.width, y: self.size.height)
            transform = transform.rotated(by: CGFloat(Double.pi))
        } else if ( self.imageOrientation == .upMirrored || self.imageOrientation == .downMirrored ) {
            transform = transform.translatedBy(x: self.size.width, y: 0)
            transform = transform.scaledBy(x: -1, y: 1)
        } else if ( self.imageOrientation == .leftMirrored || self.imageOrientation == .rightMirrored ) {
            transform = transform.translatedBy(x: self.size.height, y: 0);
            transform = transform.scaledBy(x: -1, y: 1);
        }


        if let context: CGContext = CGContext(data: nil, width: Int(self.size.width), height: Int(self.size.height),
                                       bitsPerComponent: self.cgImage!.bitsPerComponent, bytesPerRow: 0,
                                       space: self.cgImage!.colorSpace!,
                                       bitmapInfo: self.cgImage!.bitmapInfo.rawValue) {

            context.concatenate(transform)

            if ( self.imageOrientation == UIImageOrientation.left ||
                self.imageOrientation == UIImageOrientation.leftMirrored ||
                self.imageOrientation == UIImageOrientation.right ||
                self.imageOrientation == UIImageOrientation.rightMirrored ) {
                context.draw(self.cgImage!, in: CGRect(x: 0,y: 0,width: self.size.height,height: self.size.width))
            } else {
                context.draw(self.cgImage!, in: CGRect(x: 0,y: 0,width: self.size.width,height: self.size.height))
            }

            if let contextImage = context.makeImage() {
                return UIImage(cgImage: contextImage)
            }

        }

        return nil
    }
}

- Krunal

Answer 3

兼容Swift 4.1。该扩展程序避免在iOS设备端发送图像exif数据。

extension UIImage {

    func fixOrientation() -> UIImage? {

        if (imageOrientation == .up) { return self }

        var transform = CGAffineTransform.identity

        switch imageOrientation {
        case .left, .leftMirrored:
            transform = transform.translatedBy(x: size.width, y: 0.0)
            transform = transform.rotated(by: .pi / 2.0)
        case .right, .rightMirrored:
            transform = transform.translatedBy(x: 0.0, y: size.height)
            transform = transform.rotated(by: -.pi / 2.0)
        case .down, .downMirrored:
            transform = transform.translatedBy(x: size.width, y: size.height)
            transform = transform.rotated(by: .pi)
        default:
            break
        }

        switch imageOrientation {
        case .upMirrored, .downMirrored:
            transform = transform.translatedBy(x: size.width, y: 0.0)
            transform = transform.scaledBy(x: -1.0, y: 1.0)
        case .leftMirrored, .rightMirrored:
            transform = transform.translatedBy(x: size.height, y: 0.0)
            transform = transform.scaledBy(x: -1.0, y: 1.0)
        default:
            break
        }

        guard let cgImg = cgImage else { return nil }

        if let context = CGContext(data: nil,
                                   width: Int(size.width), height: Int(size.height),
                                   bitsPerComponent: cgImg.bitsPerComponent,
                                   bytesPerRow: 0, space: cgImg.colorSpace!,
                                   bitmapInfo: cgImg.bitmapInfo.rawValue) {

            context.concatenate(transform)

            if imageOrientation == .left || imageOrientation == .leftMirrored ||
                imageOrientation == .right || imageOrientation == .rightMirrored {
                context.draw(cgImg, in: CGRect(x: 0.0, y: 0.0, width: size.height, height: size.width))
            } else {
                context.draw(cgImg, in: CGRect(x: 0.0 , y: 0.0, width: size.width, height: size.height))
            }

            if let contextImage = context.makeImage() {
                return UIImage(cgImage: contextImage)
            }

        }

        return nil
    }

}

- m4f1h4rd

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欢迎来到 Stack Overflow！通常情况下，如果答案包含代码意图的解释以及为什么这样做可以解决问题而不会引入其他问题，那么它们会更有帮助。 - Neuron

@LonelyNeuron 好的，谢谢。已添加简单描述。 - m4f1h4rd