Method of and apparatus for manipulating digital data works
OwnerDavid Hiltoninventor
Life of this patent
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Abstract
A method of hiding copyright related messages within digital data works is taught. The method relies on modifying data elements in the work according to certain rules which depend on the actual message itself. The information content of the message can be extracted through a comparison of measurable characteristics of defined portions of the modified work.
Claims9
A method of manipulating a digital data work, made up of a number of data elements, to include additional data descriptive of that digital data work, comprising the steps of:
- dividing the whole or part of the work into a pattern of constituent parts, each constituent part consisting of a set of data elements and each set of data elements having a measurable characteristic;
- selecting a particular constituent part;
- modifying some or all of the set of data elements of that particular constituent part according to a given set of rules such that the measurable characteristic of that set is different from the measurable characteristic of the corresponding unmodified set of data elements, or other sets in other constituent parts,
- wherein the difference is detectable, even after the work has undergone alterations which are of at least one kind of the alterations ordinarily applied to such works, if the pattern of the constituent parts and the nature of the measurable characteristic are known, but is not otherwise readily detectable;
- and wherein the modification codes for the additional data descriptive of that digital data work.
The method of any preceding claim comprising the further step of imposing orientation markers upon the work.
The method of any preceding claim wherein the extent of the modifications at any particular region of the work depends upon the noise level in that region.
An apparatus adapted to manipulate a digital data work to include additional data descriptive of that digital data work, the work being made up of a number of data elements, and being divided into a pattern of constituent parts, each constituent part consisting of a set of data elements and each set of data elements having a measurable characteristic;
- consisting of:
- [1] a data store for storing data representing the measurable characteristics;
- [2] a processor adapted to modify some or all of the stored data in the data store representing the set of data elements of that particular constituent part according to a given set of rules such that the measurable characteristic of that set is different from the measurable characteristic of the corresponding unmodified set of data elements, or other sets in other constituent parts;
- wherein the difference is detectable, even after the work has undergone alterations which are of at least one kind of the alterations ordinarily applied to such works, if the pattern of the constituent parts is known and the nature of the measurable characteristic is known, but is not otherwise readily detectable, and the modification codes for the additional data descriptive of that digital data work.
Dependencies are inferred from the claim text.