1. An imaging controller comprising: an index calculator to calculate an index value, which is a brightness level to evaluate a brightness, for each of divided areas of images captured by a plurality of imaging units, the index value for evaluating a photographic state of each of the divided areas; an evaluation value calculator to evaluate the images and an overlapping area between the images on the basis of the index value of each divided area calculated by the index calculator and to calculate brightness level for each of the imaging units to evaluate a total brightness of the images by applying weighting to the overlapping area; and a condition determiner to determine an imaging condition including an exposure condition for each of the imaging units on the basis of the brightness level for each of the imaging units calculated by the evaluation value calculator.