| 摘要 |
An electronic appliance includes detectors that are assigned to detection zones defined on a display. The detection zones correspond to push buttons that are arranged in an operation menu displayed on the display. Each of the detectors includes a temporal difference filter. The temporal difference filter includes a detection zone image memory, a peripheral zone image memory, a subtracter, and a motion quantity calculator. The detection zone image memory stores an image of the corresponding detection zone. The peripheral zone image memory stores an image of a peripheral detection zone defined around the corresponding detection zone. The subtracter finds a difference between the image stored in the peripheral zone image memory and a present image of the peripheral detection zone. According to the difference, the motion quantity calculator calculates first data representative of the size of an object that is present in the peripheral detection zone. The electronic appliance also includes a temporal difference filter controller that generates a first detection flag according to the first data, and according to the first detection flag, generates a write stop flag to stop writing to the detection zone image memory. |
