According to one embodiment, an image processing device includes an imaging element, a lens and an image processor. Light passes through the lens toward the imaging element. A relative position of the imaging element and the lens is changeable. The image processor acquires a first image and a second image. The image processor derives a first stored image by adding at least a portion of the second image to the first image. The first image is captured by the imaging element when the relative position is in a first range. The second image is captured by the imaging element when the relative position is in a second range different from the first range.