On the Design of Pattern Sequences for Spread Spectrum Image Watermarking
Joceli Mayer, Anderson Vieira Silvério, J.C.M. Bermudez · Anais do 2002 International Telecommunications Symposium · 2002
This article investigates pattern sequences for Direct Sequence Code Division Multiple Access (DS-CDMA) spread spectrum communication of image watermarks.The problem is stated and three choices of sequence generation are proposed, namely: traditional pseudorandom generation, deterministic sequences from Walsh and Hadamard basis, and generation by Gram-Schmidt orthogonalization of pseudorandom sequences.The desirable properties for a sequence are defined and the choices are compared based on the detection reliability of the watermark.We present analysis, comparisons and conclusions about the proper choice of sequences for watermarking applications.