An optical switching system that switches optical signals in three dimensions by moving an optically transmissive microstructure. When a misfire is not detected, the hybrid vehicle operates the engine at an engine operation point at which an engine power satisfies an engine required power in a first engine operation line. The steps of reading, modifying and overwriting are performed under the control of a processor. An alternative embodiment uses an extra light source for producing input signals of known ratio. Using this method, positioning of goods on a pallet is done on the basis of the pallet and previously loaded articles. A quantization parameter calculating unit 59 calculates, from the prediction quantization parameter and the difference information, a quantization parameter of the block to be decoded.