35266077
VQ-Based Gray Watermark Hiding Scheme and Genetic Index Assignment
A vector quantisation (VQ) based watermarking scheme for hiding the gray watermark is presented. It expands the watermark size, and employs VQ index assignment procedure with genetic algorithm, called genetic index assignment (GIA), for watermarking. The gray watermark is coded by VQ, and obtained indices are translated into a binary bitstream with a much smaller size. We partition the codebook into two sub-codebooks, and use either one of them based on the value of the bit for embedding. Next, GIA is employed to find better imperceptibility of watermarked image. Experimental results show that the proposed method possesses advantages over other related methods in literature.
41865724
Improved Image Coding with Classified VQ and Side-Match VQ
A new scheme for vector quantization (VQ) is proposed in this paper. We employ side-match and classified criteria for designing VQ codebooks to combat blocking effects induced from high compression rates, and then we use the proposed algorithm to improve the reconstructed image quality. Simulation results demonstrate the better image quality to compare with that produced from conventional schemes objectively and subjectively, at the cost of reasonable encoding complexity.
13572740
Image Texture Segmentation with Ant Colony Systems
A new scheme for texture segmentation based on ant colony systems (ACS) is proposed in this paper. Texture segmentation is one of the important branches in image pattern recognition, which provides usefulness in many applications. Until now, how to find an effective way for accomplishing texture segmentation in practical applications is still a major task. In this paper, we employ wavelet coefficients and characteristics of different subbands to serve as the basis of characteristic vectors, and we use three feature-extraction elements, namely, the extrema, entropy, and energy, to compose the characteristic vector. To alleviate segmentation fragments caused from the information in high frequency bands of texture images, we integrate the fourth element, the mean variance, into the characteristic vector. Finally, we use ACS to find a trade-off between texture segmentation and fragments. Simulation results demonstrate the effectiveness and practicability of the proposed algorithm
7106859
Vector quantization based on genetic simulated annealing
Genetic algorithm (GA) has been successfully applied to codebook design for vector quantization (VQ). However, most conventional GA-based codebook design methods need long runtime because candidate solutions must be "ne tuned by LBG. In this paper, a partition-based GA is applied to codebook design, which is referred to as genetic vector quantization (GVQ). In addition, simulated annealing (SA) algorithm is also used in GVQ to get more promising results and the corresponding method is referred to as GSAVQ. Both GVQ and GSAVQ use the linear scaling technique during the calculation of objective functions and use special crossover and mutation operations in order to obtain better codebooks in much shorter CPU time. Experimental results show that both of them save more than 71}87% CPU time compared to LBG. For di!erent codebook sizes, GVQ outperforms LBG by 1.1}2.1 dB in PSNR, and GSAVQ outperforms LBG by 1.2}2.2 dB in PSNR. In addition, GVQ and GSAVQ need a little longer CPU time than, the maximum decent (MD) algorithm, but they outperform MD by 0.2}0.5 dB in PSNR. 2001 Elsevier Science B.V. All rights reserved.
14443677
An Embedding Algorithm for Multiple Watermarks
A new algorithm for embedding several watermarks into the same original source is proposed in this paper. Instead of conventional watermark embedding algorithms that embed one watermark in one specific domain, we propose algorithms for embedding multiple watermarks into different compression domains to protect the ownership of the original images. The proposed schemes for embedding and extraction in different domains vary from the existing methods reported in the literature. Simulation results show their robustness for surviving intentional attacks and, hence, their effectiveness in protecting copyrights. They are also easy to implement.
7975589
Layered access control schemes on watermarked scalable media
Intellectual property (IP) protection is a critical element in multimedia transmission and delivery systems. Conventional IP protection can be categorized into encryption and watermarking. In this paper, a structure to perform layered access control of scalable media by combining encryption and robust watermarking is proposed and implemented. By taking advantage of the nature of both encryption and watermarking, copyrights of multimedia content can be well protected. In the summated example, we assume a scalable transmission scheme over the broadcasting environment and test the effectiveness of the proposed method. The embedded watermark can be extracted with high confidence. Then, the next temporal-layer keys can be perfectly decrypted and reconstructed. Finally, the media contents are recovered and the copyrights are assured.
12419359
Primer design for multiplex PCR using a genetic algorithm
Multiplex Polymerase Chain Reaction (PCR) experiments are used for amplifying several segments of the target DNA simultaneously and thereby to conserve template DNA, reduce the experimental time, and minimize the experimental expense. The success of the experiment is dependent on primer design. However, this can be a dreary task as there are many constrains such as melting temperatures, primer length, GC content and complementarity that need to be optimized to obtain a good PCR product. Motivated by the lack of primer design tools for multiplex PCR genotypic assay, we propose a multiplex PCR primer design tool using a genetic algorithm, which is a stochastic approach based on the concept of biological evolution, biological genetics and genetic operations on chromosomes, to find an optimal selection of primer pairs for multiplex PCR experiments. The presented experimental results indicate that the proposed algorithm is capable of finding a series of primer pairs that obeies the design properties in the same tube.
3010311
On the spanning w-wide diameter of the star graph
Let u and v be any two distinct nodes of an undirected graph G, which is k -connected. A container C(u, v ) between u and v is a set of internally disjoint paths {P1, P2, . . . , Pw } between u and v where 1 ≤ w ≤ k . The width of C(u, v ) is w and the length of C(u, v ) {written as l [C(u, v )]} is max{l (Pi ) | 1 ≤ i ≤ w }. A w -container C(u, v ) is a container with width w . The w -wide distance between u and v , dw (u, v ), is min{l (C(u, v )) | C(u, v ) is a w -container}. A w -container C(u, v ) of the graph G is a w ∗-container if every node of G is incident with a path in C(u, v ). That means that the w -container C(u, v ) spans the whole graph. Let Sn be the n-dimensional star graph with n ≥ 5. It is known that Sn is bipartite. In this article, we show that, for any pair of distinct nodes u and v in different partite sets of Sn , there exists an (n − 1)∗-container C(u, v ) and the (n − 1)-wide distance d(n−1)(u, v ) is less than or equal to n! n−2 + 1. In addition, we also show the existence of a 2∗-container C(u, v ) and the 2-wide distance d2(u, v ) is bounded above by n! 2 + 1. © 2006 Wiley Periodicals, Inc. NETWORKS, Vol. 48(4), 235–249 2006
11189498
On the spanning connectivity of graphs
Abstract A k-container C ( u , v ) of G between u and v is a set of k internally disjoint paths between u and v . A k -container C ( u , v ) of G is a k * - container if it contains all vertices of G . A graph G is k * - connected if there exists a k * -container between any two distinct vertices. The spanning connectivity of G , κ * ( G ) , is defined to be the largest integer k such that G is w * -connected for all 1 ⩽ w ⩽ k if G is a 1 * -connected graph. In this paper, we prove that κ * ( G ) ⩾ 2 δ ( G ) - n ( G ) + 2 if ( n ( G ) / 2 ) + 1 ⩽ δ ( G ) ⩽ n ( G ) - 2 . Furthermore, we prove that κ * ( G - T ) ⩾ 2 δ ( G ) - n ( G ) + 2 - | T | if T is a vertex subset with | T | ⩽ 2 δ ( G ) - n ( G ) - 1 .
10374803
Hemispherical Harmonic Surface Description and Applications to Medical Image Analysis
The use of surface harmonics for rigid and nonrigid shape description is well known. In this paper we define a set of complete hemispherical harmonic basis functions on a hemisphere domain and propose a novel parametric shape description method to efficiently and flexibly represent the surfaces of anatomical structures in medical images. As the first application of hemispherical harmonic theory in shape description, our technique differs from the previous surface harmonics shape descriptors, all of which don't work efficiently on the hemisphere-like objects that often exist in medical anatomical structures (e.g., ventricles, atriums, etc.). We demonstrate the effectiveness of our approach through theoretic and experimental exploration of a set of medical image applications. Furthermore, an evaluation criterion for surface modeling efficiency is described and the comparison results demonstrated that our method outperformed the previous approaches using spherical harmonic models.
635773
Surface Alignment of 3D Spherical Harmonic Models: Application to Cardiac MRI Analysis
The spherical harmonic (SPHARM) description is a powerful surface modeling technique that can model arbitrarily shaped but simply connected 3D objects and has been used in many applications in medical imaging. Previous SPHARM techniques use the first order ellipsoid for establishing surface correspondence and aligning objects. However, this first order information may not be sufficient in many cases; a more general method for establishing surface correspondence would be to minimize the mean squared distance between two corresponding surfaces. In this paper, a new surface matching algorithm is proposed for 3D SPHARM models to achieve this goal. This algorithm employs a useful rotational property of spherical harmonic basis functions for a fast implementation. Applications of medical image analysis (e.g., spatio-temporal modeling of heart shape changes) are used to demonstrate this approach. Theoretical proofs and experimental results show that our approach is an accurate and flexible surface correspondence alignment method.