On JPEG2000 coding apparatus, the coding process is performed by discriminating an area defined by each object contained in image data and specifying type of the object, performing character recognition processing on the area discriminated as that containing a character to produce a text data and producing an XML data corresponding to said text data, adding an XML box that can store a specific data into a bit stream constructing said JPEG2000 file so as to be positioned in back of a predetermined level of wavelet decomposition and causing said XML box to store said XML data. On the other hand, on JPEG2000 decoding apparatus, the decoding process is performed by causing user to select whether to read an XML box added into a bit stream of JPEG2000 file in the middle of JPEG2000 decoding process, and processing the XML data stored in the XML box to acquire a text data.