-(void)savePictureToLibrary{    

    UIImage *img = [[UIImage imageNamed:@"image.png"];

    UIImageWriteToSavedPhotosAlbum(img, self, @selector(image:didFinishSavingWithError:contextInfo:), self);

}

- (void)image:(UIImage *)image didFinishSavingWithError:(NSError *)error contextInfo:(void *)contextInfo{

    NSString *str = @"Saved!!!";

    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Saved." message:str delegate:self cancelButtonTitle:nil otherButtonTitles:@"OK", nil];

    [alert show];

}