A noise removal device includes a noise remover, a data compressor, a data decompressor, a stillness detector, and an output selector. For a second frame succeeding a first frame, the noise remover performs noise removal on input image data of the second frame to generate noise removed data, based on the input image data of the second frame and decompressed data of the first frame. For the second frame, the output selector: selects the input image data as output image data, when the stillness detector detects that the input image data is data of a still image; and selects the noise removed data as the output image data, when the stillness detector detects that the input image data is not the data of the still image.