According to one embodiment, the image processing device includes imagers disposed on an outer circumference of a mobile object for imaging surroundings of the mobile object to generate multiple images including mutually overlapping regions, and a processor that corrects the images on the basis of one color-value mean value and another color-value mean value to generate a peripheral image by combining the corrected images. The one color-value mean value is an average of color values of a target region set in an overlapping region of one of the images. Another color-value mean value is an average of color values of a target region set in an overlapping region of another one of the images.