Image registration is essential in spread spectrum based watermark detection of a distorted image. Traditional registration approaches include the use of templates and feature matching between the distorted image and a reference image. However, neither of these techniques adequately addresses localized transformation. We propose a new registration scheme based on motion estimation between the distorted image and a reference copy. Complex wavelets provide a hierarchical framework for our motion estimation algorithm and radial basis functions provide the means to correct erroneous motion vectors. Experimental results show that our approach can estimate the distortion quite accurately and allow correct watermark detection.

Date Published: 1 August 2001
PDF: 12 pages
Proc. SPIE 4314, Security and Watermarking of Multimedia Contents III, (1 August 2001); doi: 10.1117/12.435445

Published in SPIE Proceedings Vol. 4314:
Security and Watermarking of Multimedia Contents III
Ping Wah Wong; Edward J. Delp III, Editor(s)