Patent ID: 8015410
Filing Date: 2011-09-06
Classification: G06T,H04N

Abstract:
1. A data processing apparatus operable to identify a code word present in a watermarked version of a material item, such as an image or data stream the material item composed of a plurality of units and the code word composed of a plurality of parts, each part including different data from the code word, the watermarked version formed by combining each of the plurality of parts of the code word with one of the plurality of units, the apparatus comprising a hardware recovery processor operable to recover a partial code word composed of at least one of the plurality of parts of the code word from at least one of the plurality of corresponding units of the watermarked material item, and a correlator operable to generate for the watermarked material item a dependent correlation value by correlating the partial code word with a corresponding partial stored code word that is a part of a whole stored code word, and a detector operable to determine whether the whole stored code word is present in the watermarked material item based on the dependent correlation value for the partial code word exceeding a predetermined threshold, wherein when the dependent correlation value does not exceed the predetermined threshold, the correlator is operable to iteratively increase a number of parts of the partial code word used, to increase information quantity of the recovered partial code word, each time the information quantity of the partial code word is increased, the correlator is operable to generate a dependent correlation value by correlating the partial code word having increased information quantity with a corresponding partial stored code word, the iterative increasing of the information quantity of the partial code word continuing until the whole code word is recovered by the recovery processor, and correlated with the whole stored code word by the correlator, or the predetermined threshold exceeded.