1. An image processing apparatus comprising: a processor; and memory storing computer readable instructions, when executed by the processor, causing the apparatus to function as: a document image acquiring unit configured to acquire document image data which is generated by optically reading a document and represents a document image; an area image generating unit configured to use the document image data to generate plural area image data representing plural area images that are included in the document image; and a file generating unit configured to generate a file including the plural area image data such that the plural area images are disposed in different pages, wherein the area image generating unit is configured to use one document image data to generate N-number of area image data, where N is an integer equal to or greater than 3, wherein the file generating unit is configured to generate M-number of files each of which includes one or more of the N-number of area image data, where M is an integer from 2 to (N−1), and wherein at least one of the M-number of files is a file in which two or more area images corresponding to two or more area image data of the N-number of area image data are disposed in different pages.