An apparatus, system, and method of image processing, each of which: acquires a plurality of images respectively captured with a plurality of imaging elements, the plurality of images respectively corresponding to a plurality of frames of a video; calculates, for a current frame, an evaluation value to be used for evaluating each of the plurality of images using a pixel value of at least one pixel in an overlapping area of the plurality of images; determines whether an evaluation value of each of the plurality of images in a frame preceding the current frame is stored in a memory; determines at least one correction target image from the plurality of images based on the evaluation value calculated for the current frame and a determination result indicating whether the evaluation value in the preceding frame is stored; calculates a plurality of correction amounts to be used for correcting a plurality of evaluation values in the overlapping area of the correction target image, based on the evaluation value of the correction target image; and corrects the correction target image based on the plurality of correction amounts.