The image processing apparatus includes a determination unit that determines whether a plurality of input images are a plurality of divided images or a plurality of independent images, an adding unit that adds a margin image to an edge portion of each input image, an image processing unit that performs image processing on the plurality of input images to each of which the margin image has been added when the plurality of input images are the plurality of divided images, and performs image processing on the plurality of images to each of which the margin image generated from another input image has not been added when the plurality of input images are the plurality of independent, and a synthesizing unit that generates one synthesized image by synthesizing the plurality of input images on which image processing has been performed by the image processing unit.