An image processing device includes a dimension information acquisition unit that acquires dimension information specifying dimensions of a target image formed by extracting a region of a target of an image containing the target, picked up by image pickup unit. The image processing device further includes a pickup image quality information acquisition unit that acquires pickup image quality information indicating an image quality of the region of the target in the pickup image picked up by the image pickup unit; and a resolution acquisition unit that acquires a resolution of the region of the target when the region of the target is formed in the dimensions based on the dimension information and the pickup image quality information.