A method for converting a document into a full-page image using a graphical device
interface (GDI) of an operating system is disclosed. The GDI provides objects of
the document and coordinates of the objects in the document. The document is divided
into a plurality of blocks. An address array having a plurality of address units
is established to record the coordinates of the objects. Each of the address units
corresponds to one of the blocks and is used to record positions of the objects
in the block. The positions recorded in the address units are updated according
to the coordinates of the objects provided by the GDI. A corresponding image piece
for each block is generated according to the updated positions recorded in the
corresponding address unit. All of the image pieces are merged into the full-page image.
