When a user makes some changes (cropping, red-eye removal, ...) to photos in the built-in Photos.app on iOS, the changes are not applied to the fullResolutionImage
returned by the corresponding ALAssetRepresentation
.
However, the changes are applied to the thumbnail
and the fullScreenImage
returned by the ALAssetRepresentation
.
Furthermore, information about the applied changes can be found in the ALAssetRepresentation
's metadata dictionary via the key @"AdjustmentXMP"
.
I would like to apply these changes to the fullResolutionImage
myself to preserve consistency. I've found out that on iOS6+ CIFilter
's filterArrayFromSerializedXMP: inputImageExtent:error:
can convert this XMP-metadata to an array of CIFilter
's:
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];
}
However, this works only for some filters (cropping, auto-enhance) but not for others like red-eye removal. In these cases, the CIFilter
s have no visible effect. Therefore, my questions:
- Is anyone aware of a way to create red-eye removal
CIFilter
? (In a way consistent with the Photos.app. The filter with the keykCIImageAutoAdjustRedEye
is not enough. E.g., it does not take parameters for the position of the eyes.) - Is there a possibility to generate and apply these filters under iOS 5?