1. An image processing device, comprising: an image acquisition unit that acquires images consecutively captured, while an image capture range is moved in a predetermined direction; a detection unit that detects same subject images from the images acquired by the image acquisition unit; a calculation unit that calculates evaluation values of the same subject images detected by the detection unit; a decision unit that decides, as a combination target, a specific subject image from the same subject images, based on the evaluation values calculated by the calculation unit; and a generation unit that generates a wide-range image by combining the specific subject image decided as the combination target by the decision unit with the images acquired by the acquisition unit, such that the specific subject image decided as the combination target by the decision unit is included in the wide-range image, and such that another subject image among the same subject images which is not decided as the combination target by the decision unit is not used in generating the wide-range image.