Watermarking on Compressed Image: A New Perspective
P. Santi, Claude Delph · InTech eBooks · 2012
The rest of the chapter is organized as follows: Section 2 makes a brief literature review on related works and their limitations followed by the scope of the present work.A general outline for new algorithm design of watermarking on compressed data is then highlighted in Section 3. Section 4 presents proposed watermarking method, while performance analysis is done in Section 5. Finally conclusions are drawn in Section 6 along with scope of the future works. Review of related works, limitations and scope of the workIn this section, we present a brief literature review for watermarking on compressed data with an objective to discuss their merits, limitations and finally scope of the proposed work. Related works and limitationsSome watermarking algorithms work entirely on the compressed domain such as JPEG-to-JPEG (J2J) watermarking (Wong, 2000; Wong2001).Robust watermarking scheme is proposed in (Wong & Au, 2002) using iterative spread spectrum technique (SST) in JPEG images.These methods embed different amount of watermark bits into JPEG images while maintaining good visual quality of the watermarked JPEG images.Huang et al (Huang et al., 2007) propose an effective watermark embedding method for JPEG image which can resist high compression attack and retains a good image quality.The algorithm consists of three parts, searching for the optimal embedding position, proper embedded value and the embedded/extracted processing based on quantization index modulation (QIM).Elbasi (Elbasi, 2007) propose a robust MPEG video watermarking in wavelet domain by embedding a pseudo random sequence in MPEG-1 using two bands (LL-low low and HHhigh high).They show experimentally that for one group of attacks (i.e.JPEG compression, Gaussian noise, resizing, lowpass filtering, rotation and frame dropping), the correlation with the real watermark is higher than the threshold in the LL band, and for another group of attacks (i.e.cropping, histogram equalization, contrast adjustment and gamma correction), the correlation with real watermark is higher than the threshold in the HH band.Taniguchi (Taniguchi, 2005) proposes a method that provides robustness against scaling for watermarked MPEG content using a pseudo-random sequence of block patterns and a tiled structure.Detection of the watermark information is based on a cross-correlation between the watermarked content and the watermark pattern.Basically the scaling change is detected by observing the auto-correlation peaks generated by the tiled structure.Allatar etal (Allatar at el., 2003) propose a novel watermarking method for low bit rate video that is compressed according to the advanced simple profile of MPEG-4.A simple spread spectrum watermark was embedded directly to the MPEG-4 bit-streams.A synchronization template was employed to combat cropping, scaling, and rotation.A gain control algorithm adjusts the local strength of the watermark depending on local image characteristics, in order to maximize watermark robustness and to minimize the impact on the quality of the video.He et al (He et al., 2002) propose an object based watermarking solution for MPEG4 video authentication.Nakajima et al. (Nakajima et al.,2005) proposed a high capacity data hiding method in MPEG domain utilizing the idea of zero run-level encoding.Embedding of watermark information on compressed data needs partial or full decoding depending on the domain where the watermark would be embedded in least significant bits www.intechopen.com