An image processing system includes an information processing device configured to externally receive image data and display thereon an image based on the image data, and an image scanner connected with the image processing device. The image scanner includes a scanning unit configured to scan an image on a document set thereon and to create image data of the scanned image, a detector configured to detect whether the document is removed from the scanning unit, and a controller configured to, in response to the detector detecting that the document is removed from the scanning unit after the image on the document is scanned by the scanning unit, transmit the image data created by the scanning unit to the information processing device.