How to save image document directory in ios

.h file

@interface ViewController : UIViewController <UIImagePickerControllerDelegate, UINavigationControllerDelegate>

 {

    UIImagePickerController *picker;

    UIImage *image;

}

-(IBAction)ChooseExisting;

- (IBAction)btnSave:(id)sender;

.m file

-(IBAction)ChooseExisting{

    picker = [[UIImagePickerController alloc]init];

    picker.delegate=self;

    [picker setSourceType:UIImagePickerControllerSourceTypePhotoLibrary];

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

    

}

- (IBAction)btnSave:(id)sender {    

    if (image != nil)

    {

        NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,

                                                             NSUserDomainMask, YES);

        NSString *documentsDirectory = [paths objectAtIndex:0];

        NSString* path = [documentsDirectory stringByAppendingPathComponent:

                          [NSString stringWithFormat: @"imagename.png"]];

        NSData* data = UIImagePNGRepresentation(image);

        [data writeToFile:path atomically:YES];     

    }

}

-(void) imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info{

    image = [info objectForKey:UIImagePickerControllerOriginalImage];

    [self dismissViewControllerAnimated:YES completion:NULL];

}