In an image forming apparatus, a reader reads an image of one page of an original thereby obtaining image data. A determining unit determines whether embedded data has been embedded in the image data. An extracting unit extracts the embedded data, acquires a target page number of a reading unnecessary page based on the embedded data, and saves the page number in a storage unit. A page number determining unit determines whether a page number of a next page of the original matches with the target page number. Upon the page number of the next page matching with the target page number, the reader does not read image data of the next page.