In an information embedding apparatus, an image compositing portion selectively reads an embedding pattern from a plurality of types of the embedding patterns in accordance with an embedding information for a background of a document image. The image compositing portion further composites the read embedding pattern into the background of the document image in a document image data generated based on a document data and outputs the composite document image data. The embedding pattern includes a data dot placed at a position in accordance with the embedding information, a position dot placed at a position for instructing a reference position used for identifying the position of the data dot, and an assisting dot placed at a position for assisting the instruction of the reference position by the position dot.