There is provided an image processing device including an acquisition portion that acquires image data of an image, a dividing portion that divides the acquired image into a number of blocks N (N>1), a specification portion that sequentially specifies, each time the image data of the image is newly acquired, a number of the blocks M (N≧M>1) from among the number of the blocks N, as the blocks to be updated, a filtering portion that performs filtering using a predetermined filter on the image data of the specified number of the blocks M, a counting portion that counts a number of pixels for which a filtering result is larger than a predetermined value, a first determination portion that determines whether there is an abnormality in the blocks, and a second determination portion that determines whether sabotage has occurred.