An image processing system includes an image coding device serving as a host device that outputs image data, and an image decoding device serving as a client device and including a display part that displays an image based on image data transmitted from the image coding device. The image coding device includes an image quality controller that controls the image quality of an image displayed on the display part in accordance with an operation status A of the image processing system. When the operation status is a status under which a delay of displaying an image which is caused by transmission of image data from the image coding device to the image decoding device is allowed, the image quality controller increases the image quality of an image displayed on the display part.