CIFilter 在 Swift 中旋转 UIImage

Question

应用 CIFilter 后，UIImage 正在旋转 90 度。我很惊讶这个问题在这么多年后仍然发生。是否有这些修复的快速版本：

更好的修复： iOS UIImagePickerController result image orientation after upload

原始修复： Using CoreImage to filter an image results in image rotation

Answer 1

这个怎么样（image 是你的UIImage）：

let ciImage = CIImage(image: image)?.imageByApplyingOrientation(imageOrientationToTiffOrientation(image.imageOrientation))

func imageOrientationToTiffOrientation(value: UIImageOrientation) -> Int32
{
    switch (value)
    {
    case UIImageOrientation.Up:
        return 1
    case UIImageOrientation.Down:
        return 3
    case UIImageOrientation.Left:
        return 8
    case UIImageOrientation.Right:
        return 6
    case UIImageOrientation.UpMirrored:
        return 2
    case UIImageOrientation.DownMirrored:
        return 4
    case UIImageOrientation.LeftMirrored:
        return 5
    case UIImageOrientation.RightMirrored:
        return 7
    }
}