BLINDERROR-FREEDETECTIONOF TRANSFORM-DOMAIN WATERMARKS MonaA.Sheikh andRichard G.Baraniuk Electrical & Computer Engineering Department RiceUniversity
Houston Tx · 2007
Inthis paper wepropose anewblind, error-free detection algorithm forwatermarking intransform domains. Thedetection scheme useslinear decoding techniques fromtherecent theory ofCompressive Sensing (CS), whosecentral ideais that asmall numberofnon-adaptive linear projections ofa sparse signal aresufficient forerror-free reconstruction ofthe original signal. We usethefact that natural images areapproximately sparse intheDCTorwavelet basis; withanextra step ofsparsification orscaling ofthecoefficients wecandecodeboththeoriginal imageandwatermark withzeroerror, despite notknowing thehost image. Besides being error-free, ourproposed detection algorithm haslowcomplexity compared toother blind algorithms. Itcanbeextended toany transform-domain watermarking method, andalso beusedto watermark already compressed images. Index Terms-Blind Watermark Detection, fL-decoding, Imagecompression, Transform DomainWatermarks, Compressive Sensing