UNDERWATER PHOTOGRAPHING DEVICE, CONTROL METHOD FOR UNDERWATER PHOTOGRAPHING DEVICE, AND CONTROL PROGRAM FOR UNDERWATER PHOTOGRAPHING DEVICE

摘要

An imaging unit (1) captures an image of a photographing object under water. An illumination unit (3) illuminates the photographing object. A histogram generation unit (21) divides brightness levels from the minimum to the maximum of a brightness signal included in an image signal into a plurality of brightness groups and generates histogram data indicating the distribution of the frequencies of the plurality of brightness groups. On the basis of the histogram data, a histogram analysis unit (22) analyzes how the frequencies of the plurality of brightness groups are distributed. A distance control unit (512) performs control so as to adjust the distance between the photographing object and the illumination unit (3) according to the analysis result of the histogram data.