This book constitutes the refereed proceedings of the 6th International Workshop, IWDW 2007, held in Guangzhou, China, in December 2007.
The 24 revised full papers together with 3 invited papers were carefully reviewed and selected from 81 submissions. The papers are organized in topical sections on watermark security, steganalysis, authentication, reversible data hiding, robust watermarking, poster session, theory and methods in watermarking.