-(void)takePicure

UIImagePickerController *picker = [[UIImagePickerController alloc] init];
picker.sourceType = UIImagePickerControllerSourceTypeCamera;
picker.showsCameraControls = NO;

UIView *cameraControlsView = [[UIView alloc] initWithFrame:controlsFrame];
UIButton *captureButton = [[UIButton alloc] initWithFrame:buttonFrame];
[captureButton setTitle:@"Capture" forState:UIControlStateNormal];
[captureButton addTarget:self action:@selector(buttonPressed:)
        forControlEvents:UIControlEventTouchUpInside];
[cameraControlsView addSubview:captureButton];
picker.cameraOverlayView = cameraControlsView;

- (void)buttonPressed:(id)sender {
    [NSTimer scheduledTimerWithTimeInterval:3.0f target:self
     selector:@selector(timerFired:) userInfo:nil repeats:NO];
}

- (void)timerFired:(NSTimer *)timer {
    if (whateverIsOk) {
        [self.picker takePicture];
    )
}