public void clearImages(){
  chunks.clear();
  markers.clear();
  redraw(true);
  shift_x=0;
  shift_y=0;
  zoom_level_pos=7;
  zoom_level=1;
}

public void clearImages ( ) { chunks . clear ( ) ; markers . clear ( ) ; redraw ( true ) ; shift_x = 0 ; shift_y = 0 ; zoom_level_pos = 7 ; zoom_level = 1 ; }
clears all the images in the preview .
