An image processing device acquires image data of set document sheets in a single acquiring operation, extracts from the image data document images respectively based on the document sheets, specifies a position of each document image defined on the image data, provides each document image with a first identification based on the specified positions of the document images, inputs data for creating ancillary images, provides each ancillary image based on the input data with a second identification, identifies an ancillary images as being associated with one of the document images, based on the first and second identifications, generates one or more pages of composite data, each page of the composite data containing one or more combinations each of which includes one of the document images and an ancillary image identified as being associated with the one of the document images, and outputs each page of the composite data.