An image processing apparatus has at least one standard function to be available upon start-up of the image processing apparatus itself and at least one optional function to be available by settings. The image processing apparatus includes an image input portion that inputs image data, an encoder that encodes the input image data, a main memory that stores the encoded image data, a non-volatile memory that stores a backup copy of the image data stored on the main memory, a settings portion that allows setting the optional function available, and a controller that reserves a memory area for an optional program to execute the available optional function in the main memory, and a memory area for input of the encoded image data in the main memory, the memory area being smaller than a memory area to be reserved if the optional function is unavailable.