An image watermarking algorithm via Zero Assigned Filter Banks

In this paper a new method for digital image watermarking based on Zero Assigned Filter Banks and Embedded Zero Tree Wavelet (EZW) algorithm is presented. An image is partitioned into 128 × 128 subblocks and each block is processed in a three stage decomposition structure by a filter bank which is assigned a zero around the stop band. The coefficients to be marked are chosen according to the EZW algorithm. This method not only provides a robust watermarking scheme but may also be used as an effective compression strategy. The algorithm is tested under white Gaussian noise and against JPEG compression and it is observed to be robust even when exposed to high levels of corruption. © 2005 IEEE

Approximations in compensator design: A duality

In classical controller design, poles fat to the left of dominant poles are sometimes ignored. Similarly, in some proportional-integral compensation techniques, the controller zero is placed close to the origin and design proceeds after cancelling this zero with a pole at the origin. A rigorous basis for these methods is provided, it being shown that there is a duality between the two

Polynomial characterizations of (H, F)-invariant subspaces with applications

AbstractA direct study of (H, F)-invariant subspaces associated with the polynomial fractional system model Z = PQ-1R + W is undertaken. The earlier results on the polynomial characterization of these subspaces are extended to cover the general case. For full rank transfer matrices, the smallest unobservability subspace containing im G and the largest reachability subspace in ker H are described in terms of factors of the polynomial system matrix. A new polynomial model and its superspaces play the central role in all these characterizations. The results obtained are applied to two measurement feedback problems in linear control theory, yielding geometric interpretations for two rational matrix equations

Reliable Decentralized Stabilization of Feedforward and Feedback Interconnected Systems

Synthesis of decentralized controllers that are reliable in the presence of breakdowns in the interconnections are considered for plants obtained via feedforward and feedback type interconnection schemes. The main objective is to determine the precise conditions on the plant which assure such reliable synthesis. It is shown that the central property for reliable decentralized stabilization is always an appropriate parity interlacing property among the poles of the interconnection subplants and certain blocking zeros of the overall plant. The conditions under which the stabilization of a two-channel plant is affected by the stabilization of its diagonal subplants are also obtained. The results also find application in multiple controller reliable synthesis problems. The discussion is restricted to two-channel plants. © 1992 IEE

2005 IEEE International Symposium on Signal Processing and Information Technology An Image Watermarking Algorithm via Zero Assigned Filter Banks

Abstract In this paper a new method for digital imag