Exifを付与しNSDataを作成するサンプルコード

setExifInfoData.m

- (NSData *)setExifInfoData:(UIImage *)image date:(NSString *)date {
    CGImageSourceRef cgImage = CGImageSourceCreateWithData((__bridge CFDataRef) UIImageJPEGRepresentation(image, 1), NULL);

    NSMutableDictionary *exifDict = [[NSMutableDictionary alloc] init];
    if ([StringUtil isNilToEmpty:date]) {
        NSDateFormatter *outputFormatter = [[NSDateFormatter alloc] init];
        [outputFormatter setDateFormat:@"yyyy:MM:dd HH:mm:ss"];
        NSString *original = [outputFormatter stringFromDate:[NSDate date]];
        [exifDict setObject:original forKey:(__bridge NSString *) kCGImagePropertyExifDateTimeOriginal];
        [exifDict setObject:original forKey:(__bridge NSString *) kCGImagePropertyExifDateTimeDigitized];
    } else {
        [exifDict setObject:date forKey:(__bridge NSString *) kCGImagePropertyExifDateTimeOriginal];
        [exifDict setObject:date forKey:(__bridge NSString *) kCGImagePropertyExifDateTimeDigitized];
    }

    NSMutableData *imageData = [[NSMutableData alloc] init];
    CGImageDestinationRef destination = CGImageDestinationCreateWithData((__bridge CFMutableDataRef) imageData,
            CGImageSourceGetType(cgImage),
            1,
            nil);
    CGImageDestinationAddImageFromSource(destination,
            cgImage,
            0,
            (__bridge CFDictionaryRef) [NSDictionary dictionaryWithObjectsAndKeys:
                    exifDict, (__bridge NSString *) kCGImagePropertyExifDictionary,
                    nil]);
    CGImageDestinationFinalize(destination);
    CFRelease(cgImage);
    CFRelease(destination);

    return imageData;
}