Patent ID: 7254250
Filing Date: 2007-08-07
Classification: G06T,H04N

Abstract:
1. A method of embedding a watermark bit-sequence in a data stream of symbols compressed using dictionary-based compression scheme with variable length indices, comprising: receiving a request to transmit an index value from a set of m-bit index values used to compress one or more symbols in the data stream; identifying divisions in the set of m-bit index values including a non-watermark value range, a zero-bit watermark value range and a one-bit watermark value range; determining a watermark bit value corresponding to the watermark bit sequence as either a zero-bit value or a one-bit value; transmitting the index value in the one-bit watermark value range when the watermark bit value is determined to be a one-bit value; and transmitting the index value in the zero-bit watermark value range when the watermark bit value is determined to be a zero-bit value.