某些 EXIF 元数据不会在 Swift 后更新

Question

我正在尝试更新图像的元数据，但我有好有坏。从我在博客和 Stack Overflow 上找到的示例来看，我认为我做的是正确的事情，但有些值会更新，而其他值则不会。谁能看出我哪里出错了？

    func writeMetadata(originalImage url: URL) {

        let newDestinationPath = NSTemporaryDirectory().appending("Out.jpg")
        let newDestinationURL = URL(fileURLWithPath: newDestinationPath)

        // Create source and destination
        guard let imageData = try? Data(contentsOf: url),
              let imageSource = CGImageSourceCreateWithData(imageData as CFData, nil),
              let utf = CGImageSourceGetType(imageSource),
              let destination = CGImageDestinationCreateWithURL(newDestinationURL as CFURL, utf, 1, nil) else { return }

        // Get original metadata
        guard let originalImageProperties = CGImageSourceCopyPropertiesAtIndex(imageSource, 0, nil) as? NSDictionary,
              let mutableDictionary = originalImageProperties.mutableCopy() as? NSMutableDictionary,
              let exifDictionary = mutableDictionary[kCGImagePropertyExifDictionary as String] as? NSMutableDictionary else { return }
        print("Original metadata: \(originalImageProperties)")

        // These properties successfully update
        exifDictionary["CameraOwnerName"] = "ADB"
        exifDictionary["ApertureValue"] = 1

        // This property doesn't update
        print("Date Before: \(exifDictionary[kCGImagePropertyExifDateTimeDigitized as String])")
        let dateFormatter = DateFormatter()
        dateFormatter.dateFormat = "yyyy:MM:dd HH:mm:ss"
        exifDictionary[kCGImagePropertyExifDateTimeDigitized as String] = dateFormatter.string(from: Date())
        print("Date After: \(exifDictionary[kCGImagePropertyExifDateTimeDigitized as String])")

        // Update original metadata with updated Exif dictionary
        mutableDictionary[kCGImagePropertyExifDictionary as String] = exifDictionary

        // Write new file
        CGImageDestinationAddImageFromSource(destination, imageSource, 0, mutableDictionary as CFDictionary)
        CGImageDestinationFinalize(destination)

        // Fetch updated metadata
        guard let newSource = CGImageSourceCreateWithURL(newDestinationURL as CFURL, nil),
              let newMetadata = CGImageSourceCopyPropertiesAtIndex(newSource, 0, nil) else { return }
        print("Newly updated metadata: \(newMetadata)")
    }

非常感谢任何指导！

Answer 1

我运行你的代码，运行没问题，EXIF 数据按 DateTimeDigitized 的预期更新。您是否可能检查了 DateTimeOriginal 元数据或 {TIFF} 元数据，而您没有更新？

如果要设置 DateTimeOriginal 元数据，可以使用 kCGImagePropertyExifDateTimeOriginal

键按如下方式完成

exifDictionary[kCGImagePropertyExifDateTimeOriginal as String] = dateFormatter.string(from: Date())

某些 EXIF 元数据不会在 Swift 后更新

Some EXIF metadata won't update in Swift

exif

swift