解讀XMP中繼資料中ALAssetRepresentation

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當使用者進行某些更改（裁剪，消除紅眼，...），在內建 Photos.app iOS上，這些更改將不會應用到由相應

fullResolutionImage

返回的

ALAssetRepresentation

照片.

但是，這些更改應用到

thumbnail

並由

fullScreenImage

返回的

ALAssetRepresentation

.
此外，有關應用的更改資訊可以在

ALAssetRepresentation

的中繼資料字典通過key

@"AdjustmentXMP"

發現.

我想這些更改應用到

fullResolutionImage

自己保持一致性.我發現在 iOS6的+

CIFilter

的

filterArrayFromSerializedXMP: inputImageExtent:error:

可以在此XMP中繼資料轉換的

CIFilter

數組的：

ALAssetRepresentation *rep;
NSString *xmpString = rep.metadata[@"AdjustmentXMP"];
NSData *xmpData = [xmpString dataUsingEncoding:NSUTF8StringEncoding];

CIImage *image = [CIImage imageWithCGImage:rep.fullResolutionImage];

NSError *error = nil;
NSArray *filterArray = [CIFilter filterArrayFromSerializedXMP:xmpData
inputImageExtent:image.extent
error:&error];
if (error) {
NSLog(@"Error during CIFilter creation: %@", [error localizedDescription]);
}

CIContext *context = [CIContext contextWithOptions:nil];

for (CIFilter *filter in filterArray) {
[filter setValue:image forKey:kCIInputImageKey];
image = [filter outputImage];
}

 

然而，這僅適用於某些過濾器（裁剪，自動提升），但不是為別人像去除紅眼.在這些情況下，

CIFilter

s有沒有可見的效果.因此，我的問題：

• 有沒有人知道的方式來建立紅眼消除

  CIFilter

  ？ （在與Photos.app一致的方式，與關鍵

  kCIImageAutoAdjustRedEye

  該過濾器是不夠的.例如，它沒有考慮對眼睛的位置參數.）

• 有沒有一種可能的iOS 5下產生並應用這些過濾器？

   解答  Rank --  0

 

ALAssetRepresentation* representation = [[self assetAtIndex:index] defaultRepresentation];
// create a buffer to hold the data for the asset‘s image
uint8_t *buffer = (Byte*)malloc(representation.size);// copy the data from the asset into the buffer
NSUInteger length = [representation getBytes:buffer fromOffset: 0.0 length:representation.size error:nil];

if (length==0) return nil;

// convert the buffer into a NSData object, free the buffer after

NSData *adata = [[NSData alloc] initWithBytesNoCopy:buffer length:representation.size freeWhenDone:YES];

// setup a dictionary with a UTI hint. The UTI hint identifies the type of image we are dealing with (ie. a jpeg, png, or a possible RAW file)

// specify the source hint

NSDictionary* sourceOptionsDict = [NSDictionary dictionaryWithObjectsAndKeys:

(id)[representation UTI] ,kCGImageSourceTypeIdentifierHint,

nil];

// create a CGImageSource with the NSData. A image source can contain x number of thumbnails and full images.

CGImageSourceRef sourceRef = CGImageSourceCreateWithData((CFDataRef) adata, (CFDictionaryRef) sourceOptionsDict);

[adata release];

CFDictionaryRef imagePropertiesDictionary;

// get a copy of the image properties from the CGImageSourceRef

imagePropertiesDictionary = CGImageSourceCopyPropertiesAtIndex(sourceRef,0, NULL);

CFNumberRef imageWidth = (CFNumberRef)CFDictionaryGetValue(imagePropertiesDictionary, kCGImagePropertyPixelWidth);

CFNumberRef imageHeight = (CFNumberRef)CFDictionaryGetValue(imagePropertiesDictionary, kCGImagePropertyPixelHeight);

int w = 0;

int h = 0;

CFNumberGetValue(imageWidth, kCFNumberIntType, &w);

CFNumberGetValue(imageHeight, kCFNumberIntType, &h);

// cleanup memory

CFRelease(imagePropertiesDictionary);

    

解讀XMP中繼資料中ALAssetRepresentation