An image processing system includes a host device, an input device and an information processing module. The host device includes a storage module, a first data transmission interface, a display module and a control unit. The control unit controls the display module to separately display at least one information encoding pattern at different time points. The input device includes an image capturing module, a second data transmission interface and a processing unit. The image capturing module captures a part of the at least one information encoding pattern displayed on the display module. The processing unit controls the second data transmission interface to transmit data to the first data transmission interface. The information processing module recognizes the part of the at least one information encoding pattern captured by the image capturing module, so as to control the host device or the input device to execute corresponding operation.