An image brightness level conversion method and apparatus which converts a multi-valued brightness level of an input pixel to a bi-valued brightness level using a threshold value. At least one sensor element for detecting a partial weight force is provided in each case on these carrying arms, wherein a force determining device for determining the weight force takes into consideration the partial weight forces determined by the at least three sensor elements. Accordingly, the user is able to manipulate various types of UIs, using a combination of pressure and various manipulation units.