Show only Photos in photo gallery iOS - Objective c

UIImagePickerController *picker = [[UIImagePickerController alloc] init];

picker.delegate = (id)self;

picker.allowsEditing = YES;

 picker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;

if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera])

        {

            //photo 

            picker.mediaTypes =  [[NSArray alloc] initWithObjects:(NSString *)kUTTypeImage, nil];;

        }

        

[self presentViewController:picker animated:YES completion:nil];