An image processing device includes a background noise detecting device configured to detect from image data of an image, background noise data of the image data. An image memory stores the image data, and an inputting/outputting device inputs and outputs the image data into and from the image memory. A background noise data removing device removes the background noise data from the image data outputted from the image memory by the inputting/outputting device. An on/off device turns on and off a background noise data removing operation of the background noise data removing device according to an external control signal.