Patent ID: 8395698

Claim:
An exposure determining device for determining an exposure upon pickup by an image pickup unit, the device comprising: an image acquiring unit that acquires an image being picked up by the image pickup unit at a previously determined first exposure; a light-intensity detecting unit that extracts a plurality of areas in the picked up image and detects a light intensity in each of the extracted areas; a mismatch area determining unit that determines, based on the detected light intensity in each of the areas detected by the light-intensity detecting unit, whether each of the areas is a mismatch area in which an edge is estimated to be undetected due to any one of excess and shortage of the first exposure; and when it is determined that any one of the areas is the mismatch area by the mismatch area determining unit, a correct exposure determining unit that determines, as an exposure upon pickup by the image pickup unit, a correct exposure, the correct exposure being matched with the light intensity in the mismatch area; wherein when it is determined that a number of the areas are the mismatch areas by the mismatch area determining unit, the correct exposure determining unit determines, as the exposure upon pickup by the image pickup unit, the correct exposure being matched with the light intensity in one of the mismatch areas, a difference between the correct exposure for the one of the mismatch areas and the first exposure being greatest in the differences between the first exposure and each of the correct exposures of the mismatch areas.