http://stackoverflow.com/questions/18939537/uiimagepickercontroller-crash-only-on-ios-7-ipad

gistfile1.m

+ (void) requestPhotoPermission:(void(^)(BOOL))block {
    ALAssetsLibrary* assetsLibrary = [[ALAssetsLibrary alloc] init];
    ALAuthorizationStatus authStatus = [ALAssetsLibrary authorizationStatus];
    if (authStatus == ALAuthorizationStatusAuthorized) {
        block(YES);
    } else if (authStatus == ALAuthorizationStatusDenied || authStatus == ALAuthorizationStatusRestricted) {
        block(NO);
    } else if (authStatus == ALAuthorizationStatusNotDetermined) {
        [assetsLibrary enumerateGroupsWithTypes:ALAssetsGroupAll usingBlock:^(ALAssetsGroup *group, BOOL *stop) {
            // Catch the final iteration, ignore the rest
            if (group == nil)
                dispatch_async(dispatch_get_main_queue(), ^{
                    block(YES);
                });
            *stop = YES;
        } failureBlock:^(NSError *error) {
            dispatch_async(dispatch_get_main_queue(), ^{
                block(NO);
            });
        }];
    }
}