1. An information processing apparatus having a central processing unit, comprising: a dividing unit configured to perform area dividing processing on document image data, wherein the area dividing processing divides a document image of the document image data into a plurality of areas; a designation unit configured to receive from a user an instruction for designating an area on which a character recognition processing is to be performed, from the plurality of areas divided by said dividing unit, wherein the character recognition processing analyzes a document image of the designated area and obtains text data from the designated area; a setting unit configured to receive from the user an instruction for setting an index item which is to be related with text data to be obtained from the designated area by the character recognition processing; a generation unit configured to generate index extraction information indicating the area designated by said designation unit and the index item set by said setting unit, the index extraction information being constructed for use by an information processing apparatus to perform the character recognition processing on the designated area and to relate text data obtained from the designated area by the character recognition processing with the set index item; and a combining unit configured to generate combined data by combining the index extraction information generated by said generation unit and form image data corresponding to the document image data, wherein if the combined data is printed and a printed image of the combined data is scanned, an information processing apparatus obtains the index extraction information from the scanned image, performs the character recognition processing on the area of the scanned image indicated by the obtained index extraction information and relates text data obtained from the area of the scanned image by the character recognition processing with the index item indicated by the obtained index extraction information.