| 摘要 |
PROBLEM TO BE SOLVED: To provide an autofocusing device capable of accurately detecting a focusing position even when the focusing position can not be detected by conventional contrast detecting method in the case that a glossy metallic surface is observed. SOLUTION: In this autofocusing device, the complexity of an obtained image is detected, and a position where the complexity becomes maximum is adopted as a focusing position. For example, a video signal is differentiated, the number of switching points (inflection points) of change is calculated, and the position where the measured value is maximum is defined as the focusing position F. Or, position where the frequency of the high-frequency component of the video signal is maximum is defined as the focusing position F. Based on the complexity of an image, the accurate focusing position F can be detected even in the case two higher parts appear on contrast curve obtained by the conventional contrast detecting method and the peak values P(a) and P(b) do not appear on the position F. |
