Question

我正在使用PhotoKit编辑照片，我需要保留原始照片中的元数据。为此，我保存元数据，然后将其提供给options中的CGImageDestinationAddImage参数。我能够最终确定它并将其成功写入磁盘，但是当我调用performChanges提交资产编辑时，它会失败。如果我为nil提供options，它就会成功。这里出了什么问题？

asset.requestContentEditingInputWithOptions(options) { (input: PHContentEditingInput!, _) -> Void in
    //get full image
    let url = input.fullSizeImageURL
    let inputImage = CIImage(contentsOfURL: url)

    //get orginal photo's metadata
    let originalImageData = NSData(contentsOfURL: url)!
    let imageSource = CGImageSourceCreateWithData(originalImageData, nil)
    let metadata: CFDictionaryRef = CGImageSourceCopyPropertiesAtIndex(imageSource, 0, nil)
    println(metadata) //prints all the metadata, yay!

    //do some processing on original photo here and create an output CIImage...

    //save to disk
    let dataRef = CFDataCreateMutable(nil, 0)
    let destination = CGImageDestinationCreateWithData(dataRef, CGImageSourceGetType(imageSource), 1, nil)
    let eaglContext = EAGLContext(API: .OpenGLES2)
    let ciContext = CIContext(EAGLContext: eaglContext)
    let cgImage = ContextStruct.ciContext!.createCGImage(outputPhoto, fromRect: outputPhoto.extent())
    CGImageDestinationAddImage(destination, cgImage, metadata) //metadata is problematic - replacing with nil causes it to work

    if CGImageDestinationFinalize(destination) {
        let contentEditingOutput = PHContentEditingOutput(contentEditingInput: input)
        contentEditingOutput.adjustmentData = "something"

        let imageData: NSData = dataRef
        let success = imageData.writeToURL(contentEditingOutput.renderedContentURL, options: .AtomicWrite, error: _)
        if success {
            PHPhotoLibrary.sharedPhotoLibrary().performChanges({ () -> Void in
                let request = PHAssetChangeRequest(forAsset: asset)
                request.contentEditingOutput = contentEditingOutput
            }, completionHandler: { (success: Bool, error: NSError!) -> Void in
                if success == false { println('failed to commit image edit: \(error)') } //fails unless metadata is replaced with nil above
            })
        }
    }
})

错误是：Error Domain=NSCocoaErrorDomain Code=-1 "The operation couldn’t be completed. (Cocoa error -1.)

Answer 1

为了编辑照片，似乎必须填写adjustementData对象的PHContentEditingOutput属性。

Answer 2

元数据中的某些键似乎会导致失败。这有效：

NSArray *validMetadataKeys = @[
    (NSString *)kCGImagePropertyTIFFDictionary,
    (NSString *)kCGImagePropertyGIFDictionary,
    (NSString *)kCGImagePropertyJFIFDictionary,
    (NSString *)kCGImagePropertyExifDictionary,
    (NSString *)kCGImagePropertyPNGDictionary,
    (NSString *)kCGImagePropertyIPTCDictionary,
    (NSString *)kCGImagePropertyGPSDictionary,
    (NSString *)kCGImagePropertyRawDictionary,
    (NSString *)kCGImagePropertyCIFFDictionary,
    (NSString *)kCGImageProperty8BIMDictionary,
    (NSString *)kCGImagePropertyDNGDictionary,
    (NSString *)kCGImagePropertyExifAuxDictionary,
];

NSMutableDictionary *validMetadata = [NSMutableDictionary dictionary];
[metadata enumerateKeysAndObjectsUsingBlock:^(id key, id obj, BOOL *stop) {
    if ([validMetadataKeys containsObject:key]) {
        validMetadata[key] = obj;
    }
}];

// your CGImage stuff

CGImageDestinationAddImageFromSource(destination, imgSource, 0, (__bridge CFDictionaryRef)validMetadata);

Answer 3

我有完全相同的问题，我已提交雷达rdar：// 21057247。我尝试使用TSI记录案例，但我被告知要提交雷达。

Answer 4

//如果资产不允许所请求的更改类型，这些方法将引发异常，在资产上调用canPerformEditOperation：以确定是否允许编辑操作的类型。

（instancetype）changeRequestForAsset：（PHAsset *）asset;

我认为这是因为Apple不希望您更改metaData。您可以尝试以下方法，也许可以创建一个新方法。

（instancetype）creationRequestForAssetFromImage：（UIImage *）image;
（instancetype）creationRequestForAssetFromImageAtFileURL：（NSURL *）fileURL;
（instancetype）creationRequestForAssetFromVideoAtFileURL：（NSURL *）fileURL;

Answer 5

我们应该将新图像的数据写入我们通过

获取的URL

                let theExportURL = output.renderedContentURL

就我而言，我这样做......

                let outputData = UIImagePNGRepresentation(bakedImage)

在运行时我收到了错误

Error Domain=NSCocoaErrorDomain Code=-1 "The operation couldn’t be completed. (Cocoa error -1.)

但是当我开始导出这样的数据时......

let outputData = UIImageJPEGRepresentation(bakedImage, 1)

有效。这里记录了...... https://developer.apple.com/library/prerelease/ios/documentation/Photos/Reference/PHContentEditingOutput_Class/index.html

这个问题在这里得到了回答...... https://stackoverflow.com/a/28362235

将元数据应用于图像会导致performChanges请求失败

5 个答案: