Question

当用户对iOS上内置的 Photos.app 中的照片进行一些更改（裁剪，消除红眼......等）时，更改不会应用于{{ 1}}由相应的fullResolutionImage返回。

但是，更改将应用于ALAssetRepresentation和thumbnail返回的fullScreenImage。此外，有关所应用更改的信息可以通过密钥ALAssetRepresentation在ALAssetRepresentation的元数据字典中找到。

我想将这些更改应用于@"AdjustmentXMP"我自己以保持一致性。我发现 iOS6 + fullResolutionImage的{{1}}可以将此XMP元数据转换为CIFilter的数组：

filterArrayFromSerializedXMP:                              inputImageExtent:error:

但是，这仅适用于某些滤镜（裁剪，自动增强），但不适用于其他滤镜，如红眼消除。在这些情况下，CIFilter没有明显的效果。因此，我的问题是：

是否有人知道如何创建红眼消除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]; }？（以与Photos.app一致的方式。使用键CIFilter的过滤器是不够的。例如，它不采用眼睛位置的参数。）
是否有可能在iOS 5下生成并应用这些过滤器？

Answer 1

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, and free the buffer after.

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

// Set up a dictionary with a UTI hint. The UTI hint identifies the type
// of image we are dealing with (that is, 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);

// Clean up memory

CFRelease(imagePropertiesDictionary);

解释ALAssetRepresentation中的XMP元数据

1 个答案: