IMAGE SENSOR

摘要

PURPOSE:To extract a stable change image and to eliminate an erroneous report and the missing of a report by providing a means which decides whether or not the mean value of the brightness level of a current image stored in a current image storage means and a deviation value calculated by a deviation value calculating means are within proper ranges. CONSTITUTION:The means value of the brightness level of current image data stored successively in the current image storage means 3 is calculated by a mean value calculating means 10 and the mean value decision means 11 decides whether or not illuminance is deficient. When this mean value is smaller than a value set by a parameter setting means 13, it is decided that the illuminance is deficient enough to cause malfunction. In this state, decision processing following a change image extracting means 7 is made ineffective to preclude the malfunction due to the deficiency in illuminance.