A semiconductor device includes an image acquisition circuit which acquires a plurality of captured image data obtained by capturing a plurality of images, an estimation source image generation circuit which cancels effects of initial color adjustment processing on each captured image data to generate image data of a plurality of estimation source images, a readjustment circuit which divides each estimation source image into a plurality of processing regions to perform color balance readjustment processing for each processing region, and an image synthesis circuit which synthesizes the image data of the plurality of estimation source images so that overlapping regions included in the estimation source images overlap each other to generate image data of a synthesized image.