To provide an image processing device which restrains coloring in an exposure error correction process for synthesizing a plurality of images.

The image processing device includes: determination means for determining a reference image from among a plurality of images on the basis of pixel values of the plurality of images; correction gain calculation means for calculating for each of the plurality of images a correction gain for matching a signal level of the plurality of images with a signal level determined according to the signal level of the reference image; and correction means for correcting each of the plurality of images by using the correction gain to generate a plurality of corrected images. The determination means determines the reference image in such a way that all the correction gain values calculated by the calculation means are equal to or greater than 1.