IMAGE PICKUP DEVICE, ITS METHOD AND COMPUTER READABLE STORAGE MEDIUM

摘要

PROBLEM TO BE SOLVED: To eliminate a release lag and to execute photographing without missing a shutter chance by providing a clamp processing means for clamp- processing an image signal in accordance with an image pickup mode or the like. SOLUTION: A control part 106 performs control so that one of the output of average value processing parts 104 and 105 is validated in accordance with a mode select signal. Then clamp processing for an optical black period is changed by the selected mode so that a release lag presence mode is selected when clamp processing with high precision is required and a release lag absence mode is selected when photographing is desired to be executed without missing the shutter chance. When photographing is executed without caring the shutter chance, preliminary image picking-up is executed to obtain an average value from the total sum concerning the optical black period and the clamp processing for obtaining a reference level with high precision is executed so that photographing is executed without missing the shutter chance.