5. The method of claim 2 , the subsequent detection of said information in a suspect page of a document copy being accomplished through steps of: providing a digitized suspect page image having at least one image plane, each said image plane being represented by an image array having brightness data for a plurality of pixels, each of said pixels having at least one color component and having a pixel position; recomputing the first set of candidate positions for embedding speckles into the page image based on said information to be embedded; recomputing the second set of candidate positions for embedding ghost speckles into the page image based on said information to be embedded; geometrically aligning said suspect page image with the page image; determining at each black speckle position whether the suspect page image had a nearby black speckle; computing the number of black speckle positions for which that suspect page image had a black speckle nearby; determining at each ghost speckle position whether the suspect page image had a nearby black speckle; computing the number of ghost speckle positions for which that suspect page image had a black speckle nearby; and determining whether the suspect printed page possessed said information to be embedded.
5. The method of claim 2 , the subsequent detection of said information in a suspect page of a document copy being accomplished through steps of: providing a digitized suspect page image having at least one image plane, each said image plane being represented by an image array having brightness data for a plurality of pixels, each of said pixels having at least one color component and having a pixel position; recomputing the first set of candidate positions for embedding speckles into the page image based on said information to be embedded; recomputing the second set of candidate positions for embedding ghost speckles into the page image based on said information to be embedded; geometrically aligning said suspect page image with the page image; determining at each black speckle position whether the suspect page image had a nearby black speckle; computing the number of black speckle positions for which that suspect page image had a black speckle nearby; determining at each ghost speckle position whether the suspect page image had a nearby black speckle; computing the number of ghost speckle positions for which that suspect page image had a black speckle nearby; and determining whether the suspect printed page possessed said information to be embedded. 7. The method of claim 5 , wherein the subsequently detecting the additional information in a suspect page of a document copy includes: recomputing the third set of candidate positions for embedding white speckles into the page image based on said information to be embedded; determining at each white speckle position whether the suspect page image had a nearby white speckle; computing the number of white speckle positions for which that suspect page image had a white speckle nearby; and determining whether the suspect printed page possessed the additional information to be embedded based on: the number of white speckle positions, and the number of white speckle positions for which the suspect page had a nearby white speckle.