The structure of an imaging device is simplified. An imaging device capable of imaging without a lens or an image processing method is provided. Image data which is out of focus is sharpened. An image processing method of image data in which a plurality of pixels are arranged is provided. Adjacent two pixels are each divided into a first region showing the same pixel value between the adjacent two pixels and a second region other than the first region, an initial value is supplied to the second region of an endmost pixel of the image data, and the pixel values of the first regions and the second regions of the plurality of arranged pixels are determined inductively and sequentially on the basis of the initial value.