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A DCT-Based Blind Watermarking Algorithm for Vector Digital Maps
Abstract
This paper presented a new DCT-based watermarking algorithm for vector digital maps. A watermark bit is embedded by modifying the relationship of several high-frequency coefficients in DCT domain. To enhance data accuracy and robustness of the watermark, we proposed a Double Error Estimation method. This method allowed watermarks to be embedded when the vertices with distortion are smaller than thresholds. Experiments show that the watermarks are resilient to random noise, general geometric transformation, data scrambling and cropping. The algorithm is blind and it is easy to implement.
... Based on the embedding domains as well as the accuracy requirements of the watermarked data, watermarking techniques are divided into several categories such as spatial domain-based watermarking, frequency domain-based watermarking, reversible watermarking, lossless watermarking, and zero-watermarking. Research on watermarking using techniques of embedding information into the spatial domain (coordinates of objects) can be mentioned as [3][4][5][6][7][8][9], techniques of embedding information into the frequency domain such as [10][11][12]. Reversible watermarking techniques for vector geographic data are performed in [13][14][15][16][17][18]. In [19,20], the studies of watermarking without losing information based on the storage order are presented. ...
... We embedded the copyright information (called watermark) into the testing data to create layers of vector geographic data that have been embedded with copyright information with an error of 10 units (i.e., degree or meter depends on the map projection). 11 ...
Vector geographic data play an important role in the natural resources and environment sector and other location information services. This is also one of the types of data where the cost to create it is relatively large because of the difficulty in surveying, collecting, and authorizing. The rapid development of the Internet has created many advantages in the distribution, exploitation, and use of vector geographic data, but it also gives rise to many problems such as duplication, redistribution, forgery, and illegal data use. The theft on the Internet is becoming more and more sophisticated and the number of violations is increasing, showing the urgent need to research and develop an effective solution to protect the copyright of vector geographic data and prevent them from being illegally collected and used. Among the major studies and solutions, digital watermarking emerges as an effective method and is an active research area for copyright protection. Towards a good solution for copyright protection of vector geographic data, our study proposes a new algorithm with three main contributions, including: (1) generating short, pseudo-random meaningful watermarks to increase robustness and to enable automated as well as visual manual verifying; (2) building a uniformly distributed mapping between the vertex coordinates and the watermark bit indexes to increase the robustness of the watermarks; and (3) integrate two types of watermarks, namely, spatial domain-based watermarking and zero-watermarking to be resistant to most common attacks on geographic vector data. The algorithm also allows working on all types of vector geographic data, including points, polylines, and polygons.
... Based on the embedding domains as well as the accuracy requirements of the watermarked data, watermarking techniques are divided into several categories such as spatial domain-based watermarking, frequency domainbased watermarking, reversible watermarking, lossless watermarking, and zero-watermarking. Research on watermarking using techniques of embedding information into the spatial domain (coordinates of objects) can be mentioned as [3][4][5][6][7][8][9], techniques of embedding information into the frequency domain such as [10][11][12]. Reversible watermarking techniques for vector geographic data are performed in [13][14][15][16][17][18]. In [19,20], the studies of watermarking without losing information based on the storage order are presented. ...
Vector geographic data play an important role in the natural resources and environment sector as well as in other location information services. This is also one of the types of data where the cost to create it is relatively large because of the difficulty in surveying, collecting, and authorizing. The rapid development of the Internet has created many advantages in the distribution, exploitation, and use of vector geographic data, but it also gives rise to many problems such as duplication, redistribution, forgery, and illegal data use. The theft on the Internet is becoming more and more sophisticated and the number of violations is increasing, showing the urgent need to research and develop an effective solution to protect the copyright of vector geographic data and prevent them from being illegally collected and used. Among the major studies and solutions, digital watermarking emerges as an effective method and is an active research area for copyright protection. Towards a good solution for copyright protection of vector geographic data, our study proposes a new algorithm with three main contributions, including: (1) generating short, pseudo-random meaningful watermarks to in-crease robustness and to enable automated as well as visual manual verifying; (2) building a uniformly distributed mapping between the vertex coordinates and the watermark bit indexes to increase the robustness of the watermarks; and (3) integrating two types of watermarks, namely, spatial domain-based watermarking and zero-watermarking to be resistant to most common attacks on geographic vector data. The algorithm works on all types of vector geographic data, including points, polylines, and polygons.
... The experimental results showed that their watermarking algorithm had a good resistance to geometric attacks but a poor invisibility. Wang et al. [30] embedded the watermark in the high-frequency coefficients of the DCT domain while also developing an error control method, which helps to reduce distortion after the watermark embedding. In summary, the frequency domain watermarking of the vector geographic data is gaining interest, but due to the nature of the algorithms, it is challenging to withstand multiple attacks at once, and the position of the watermark information during embedding is highly random, making it challenging to control the invisibility. ...
Traditional frequency-domain watermarking algorithms for vector geographic data suffer from disadvantages such as the random watermark embedding position, unpredictable embedding strength, and difficulty in resisting multiple attacks at the same time. To address these problems, we propose a novel watermarking algorithm based on the geometric invariance of the ratios of discrete wavelet transform (DWT) and complex singular value decomposition (CSVD) coefficients, which embeds the watermark information in a new embedding domain. The proposed scheme first extracts feature points from the original vector geographic data using the Douglas–Peucker algorithm, and then constructs a complex sequence based on the feature points set. The two-level DWT is then performed on the complex sequence to obtain the low frequency coefficients (L2) and high frequency coefficients (H2). On this premise, the CSVD algorithm is utilized to calculate the singular values of L2 and H2, and the ratio of the singular values of L2 and H2 is acquired as the watermark embedding domain. During the watermark embedding process, a new watermark sequence is created by the fusion of the original watermark index value and bits value to improve the recognition of the watermark information, and the decimal part at different positions of the ratio is altered by the new watermark sequence to control the watermark embedding strength. The experimental results show that the proposed watermarking algorithm is not only robust to common attacks such as geometric, cropping, simplification, and coordinate point editing, but also can extract watermark images with a high probability under random multiple attacks.
... For the robust watermarking technology in the traditional sense, the main consideration is the embedding/detection of a single watermark information. By the embedding position of watermark, it can be divided into: 1) the spatial domain watermarking algorithm, i.e. directly modifying the spatial data values to embed the watermark information [1][2][3][4][5][6] ; 2) the transform domain watermarking algorithm, i.e. using mathematical tools including DFT, DCT, DWT and Contourlet to transform the frequency domain of data, and embed watermark information in the transform domain coefficient [7][8][9][10][11][12][13] . When the traditional robust watermarking technology is applied to data copyright protection and data distribution, the single user tracking and other fields cannot solve new problems caused by the multi-level distribution and circulation of data, such as multi-user tracking and multicopyright protection. ...
This paper presents a multi-level digital watermarking algorithm suitable for raster geographic data. First, the new problems caused by the multi-level distribution of raster geographic data and its impact on watermark embedding/detection are analyzed; and then, a watermark information segmentation mechanism is designed, the multi-level watermark embedding strategy is established on this basis, thereby building the multi-level digital watermarking algorithm of raster geographic data based on the watermark segmentation mechanism with the traditional robust digital watermarking algorithm as the prototype; finally, the experimental comparison and analysis of the multi-level watermarking algorithm and the prototype algorithm are made. Results show that the proposed multi-level digital watermarking algorithm not only maintains the performance of the prototype algorithm, but also effectively solves new problems caused by the multi-level circulation of raster geographic data, such as multi-copyright protection and multi-user tracking, and has a high practical value.
... In frequency domain approaches, the watermark is embedded in the frequency coefficients after the spatial data are transformed, e.g., the coefficients of the discrete Fourier transform (DFT) [9], the discrete cosine transform (DCT) [24], and the discrete wavelet transform (DWT) [27]. Extensive sensitivity of HVS to the DCT [11] and inherent compatibility with JPEG makes the DCT domain a convenient choice for watermarking an image. ...
Watermarking plays an import role in digital copyright protection. It enables copyright owners to embed invisible watermarks within copies of data before distribution. However, most existing watermarking algorithms for 2D vector maps use either spatial domain methods, e.g., the Least Significant Bit or frequency domain methods, e.g., discrete Fourier transform (DFT), and very few algorithms combine the two domains. In order to improve the robustness of watermarks to against more common attacks, a novel algorithm using a combination of spatial and frequency domains is presented. Both the spatial domain and the frequency domain can be used for watermark embedding. Obviously, the advantages of each method are retained and the disadvantages of each method are offset by complementation. The watermark was also shuffled before embedding. A one-way hash function was used to map the watermark and 2D vector map. By using two different methods, one part of the watermark was embedded into the spatial domain first and another part of the watermark was embedded into the DFT domain. Additionally, the watermark was embedded multiple times. No original map data are required for the watermark extraction procedure. Analysis shows that the distortions of the watermarked data are extremely small, and the algorithm is more robust than methods using a single domain. It can resist the most common attacks, such as vertex insertion and removal, cropping, compression, reordering, and data format conversion attacks. It is also robust against rotation scaling and translation attacks.
... The watermarking is considered as an efficient technique to protect copyright and ownership of vector data [1]. As we know, the traditional watermarking techniques embed the watermarking information in the host data by modifying the coordinate values in the space domain [2]- [6] or the frequency domain [7]- [10]. However, these watermarking techniques may cause some damages to the sensitive information presented in the cover-vector data. ...
With the increasing demand for copyright protection of high-precision and sensitive vector data in Geographical Information System (GIS), research on lossless watermarking has attracted more and more attention. In this paper, a new lossless watermarking method based on line pairs is proposed. Firstly, the points and polygons are unified into the polylines, and then every two adjacent polylines are combined into a line pair. Besides, the storage direction and the interior angle of the line pairs are analyzed. Secondly, the watermark bit is determined by the interior angle of each line pair. Then, the watermark information is embedded by judging whether the storage direction of each line pair and the watermark bit is the same. Finally, experimental results verify that the proposed method works effectively for the data of the points, polylines and polygons, and has good invisibility without damaging the vector data. In addition, compared with the existing algorithm, the proposed method achieves higher robustness against geometric attacks, such as translating, rotating, and scaling the vector data.
... The spatial domain watermarking algorithm uses quantification, coordinate mapping, and other methods to embed the watermark by modifying the vector data coordinate values within the error tolerance, thus achieving strong resistance to addition and deletion attacks [20][21][22][23][24]. The frequency domain watermarking algorithm embeds the watermark into the coordinate transform domain coefficients such as DFT (discrete Fourier transform), DCT (discrete cosine transform), DWT (discrete wavelet transform), which improves the ability of the algorithm to resist attacks such as noise and translation [25][26][27][28]. The geometric domain-based watermarking algorithm embeds the watermark into the geographic data geometric features, including angle, distance, arc length, and can be more resistant to geometric attacks such as rotation, scaling, and translation [29][30][31][32]. ...
There is undoubtedly a groundswell of support for the concept of geographic data sharing with the rapid development and wide-ranging application of geographic information science. However, copyright protection and infringement detection in the process of geographic data sharing has always been an important issue that needs to be addressed urgently. In this paper, we present a novel infringement detection method for GIS vector data to compensate for the shortcomings of vector data digital watermarking technology in infringement detection. The method determines whether infringement exists by the duplication degree between the original data and the vector data to be detected in three features including feature features, included angle features and vertex features which gets by using the spatial information of vector data to perform the feature matching based on GeoJSON format data. The experimental results indicate that the proposed algorithm can effectively resist common geometric attacks, such as interpolation attack, deletion attack, similarity transformation attack, feature order scrambling attack, and feature simplification attack, on vector data, which proves that the proposed algorithm has excellent robustness and meets the requirements of practical application.
... Characteristics file vector map is very different from the image or audio as watermark embedding media.For it takes a different technique for inserting a information in the vector map. Some existing research has proposed the use of robust digital watermarking onthe transformation domain of vector map using data transformation algorithms based upon DFT [2], IWT (Integer Wavelet Transform) [17], and DCT [18]- [20]. Only two existing studies that were specifically carried out for the purposes of vector map copyright protection [2], [17]. ...
Automation of generating hardware description language code from neural networks models can highly decrease time of implementation those networks into a digital devices, thus significant money savings. To implement the neural network into hardware designer, it is required to translate generated model into device structure. VHDL language is used to describe those networks into hardware. VHDL code has been proposed to implement ANNs as well as to present simulation results with floating point arithmetic of the earth station and the satellite power systems using ModelSim PE 6.6 simulator tool. Integration between MATLAB and VHDL is used to save execution time of computation. The results shows that a good agreement between MATLAB and VHDL and a fast/flexible feed forward NN which is capable of dealing with floating point arithmetic operations; minimum number of CLB slices; and good speed of performance. FPGA synthesis results are obtained with view RTL schematic and technology schematic from Xilinix tool. Minimum number of utilized resources is obtained by using Xilinix VERTIX5.
Previous studies on zero-watermarking algorithms for vector geographic data focus on improving the robustness against geometrical attacks, compression attacks and object attacks. However, there are limited zero-watermarking algorithms against projection transformation. In this study, we proposed a zero-watermarking algorithm for vector geographic data based on feature invariants. After any projection transformation of vector geographic data, the number of vertices and relative storage order of objects keep consistent. Therefore, the number of vertices and relative storage order of objects can be considered as the feature invariants. The proposed algorithm consists of three steps. Firstly, according to the relative storage order of objects, the watermark bit is determined by comparing the number of vertices between any two objects. Secondly, the watermark index is calculated by the number of vertices of two objects. Then, a feature matrix is constructed by combining the watermark bit and the watermark index. Finally, the XOR operation is performed between the feature matrix and the scrambled watermark image to generate the zero-watermark image. The experimental results show that the watermark information with NC of 1.0 can be detected from the vector geographic data after any projection transformation, which shows that the algorithm can resist any projection transformation. At the same time, the useful watermark information with minimum NC values of 1.0, 0.911, 0.84, and 1.0 can be detected from the vector geographic data after the geometrical attack, object addition attack, object deletion attack and precision reduction attack. Therefore, the proposed algorithm can effectively against geometrical attacks, object addition attacks, object deletion attacks and precision reduction attacks, showing superior performance compared with previous algorithms.
Most researches on zero-watermarking algorithms for vector geographic data focus on improving the robustness against geometrical attacks, compression attacks and object attacks. However, there are few zero-watermarking algorithms against projection transformation. We proposed a zero-watermarking algorithm for vector geographic data based on feature invariants. After any projection transformation of vector geographic data, the number of vertices and relative storage order of objects does not change. Therefore, the number of vertices and relative storage order of objects can be considered as the feature invariants. Firstly, according to relative storage order of objects, the watermark bit is determined by comparing the number of vertices between any two objects. Secondly, the watermark index is calculated by the number of vertices of two objects. Then, a feature matrix is constructed combining the watermark bit and the watermark index. Finally, the XOR operation is performed between the feature matrix and the scrambled watermark image to generate the zero-watermark image. The experiments show that the watermark can be detected from the vector geographic data after any projection transformation. And this algorithm can effectively against geometrical attacks, object attacks and precision reduction attacks, showing superior performance compared with previous algorithms.
The rapid development of technology has made archival and transmission of multimedia information such as music, image, and video very convenient. However, it has also introduced new challenges related to privacy and security of data. Therefore, there is a compelling need for ensuring of authenticity and protection of ownership. For providing security of digital data, various techniques are used like encryption, decryption, cryptography, and digital watermarking. Digital watermarking is a technique of embedding selected user information into the digital content like image, video, speech, music. The watermarking algorithm should be able to detect intentional tampering of the original data and retain its integrity within the content even after various manipulation attacks like compression, enhancement, cropping, filtering.
Most of current watermarking algorithms for GIS vector data embed copyright information by means of modifying the coordinate values, which will do harm to its quality and accuracy. To preserve the fidelity of vector line data and protect its copyright at the same time, a lossless watermarking algorithm is proposed based on storage feature in this paper. Firstly, the superiority of embedding watermark based on storage feature is demonstrated theoretically and technically. Then, the basic concepts and operations on storage feature have been defined including length and angle of the polyline feature. In the process of embedding watermark, the watermark information is embedded into directions of polyline feature by the quantitative mechanism, while the positions of embedding watermark are determined by the feature length. Hence, the watermark can be extracted by the same geometric features without original data or watermark. Finally, experiments have been conducted to show that coordinate values remain unchanged after embedding watermark. Moreover, experimental results are presented to illustrate the effectiveness of the method.
Due to rapid growth of distributed network and Internet, it becomes easy for data providers and users to access, manage, and share voluminous geospatial data in digital form. Even though a consistent and reliable means are available for storing, managing and sharing geospatial data, very little attention has been given towards security, access control, and privacy policies. With Internet, it becomes very easy to distribute and copy geospatial data. Therefore, it becomes necessary to protect geospatial data from illegal and unauthorized usage. Security mechanism should be enforced at geospatial data storage, dissemination, and at data retrieval to protect geospatial data from illicit users. In this paper, we define unique security requirements for protection of geospatial data and give an overview on current approaches being used for secure distribution and management of spatial data at storage and dissemination with their limitations and the research challenges.
This study proposed a new approach of copyright protection for vector map using robust watermarking on FFT algorithm. A copyright marker inserted in vector map as the watermark. In addition to data origin authentication capabilities watermark, RSA cryptographic algorithm is used when generating the watermark. Quality measurement of the results was based on the three characteristics of digital watermarking: (1) invisibility using RMSE calculations, (2) fidelity with the farthest distance and (3) NC calculation and gemotrical level of robustness against attacks. Result of experiments showed that the approach used in this study succeeded in inserting copyright as watermark on vector maps. Invisibility test showed good results, demonstrated by RMSE close to zero. Fidelity of the watermarked map was also maintained. Level of watermark robustness against geometric attacks on vector map results has been maintained within the limits that these attacks do not affect the watermark bit value directly.
In this paper we propose a new digital watermarking method to prevent illegal copying of digital cadastral maps. These maps have special features such as objects adjacency and frequently update, and are highly accurate. The proposed method used the closest pair of points and DWT (Discrete Wavelet Transform) coefficient to embed watermarks into the latter. The experimental results showed that this method supports fidelity and is robust to division of land, annexation, rotation, and translation.
Due to rapid growth of distributed network and Internet, it becomes easy for data providers and users toaccess, manage, and share voluminous geospatial data in digital form. With Internet, it becomes very easyto distribute and copy geospatial data. Therefore, it becomes necessary to protect geospatial data fromillegal and unauthorized usage. The increase availability of tools and techniques to access and disseminategeospatial data has made more urgent to protect it. Security mechanism should be enforced at geospatialdata storage, dissemination, and at data retrieval to protect geospatial data from illicit users. In this paper,conceptual framework for geospatial data security is proposed by considering unique security requirementsof geospatial data.
Watermarking schemes for copyright protection of point cloud representation of 3D models operate only on the geometric data, and are also applicable to mesh based representations of 3D models, defined using geometry and topological information. For building such generic copyright schemes for 3D models, this paper presents a robust spatial blind watermarking mechanism for 3D point sampled geometry. To find the order in which points are to be encoded/decoded, a clustering approach is proposed. The points are divided into clusters, and ordering is achieved using inter-cluster and intra-cluster ordering. Inter-cluster ordering achieves local ordering of points, whereas intra-cluster ordering does it globally. Once ordered, a sequence of clusters is chosen based on nearest neighbor heuristic. An extension of quantization index of bit encoding scheme is proposed, and used to encode and decode inside the clusters. The encoding mechanism makes the technique robust against uniform affine transformations (rotation, scaling, and transformation), reordering attack and topology altering (e.g. retriangulation) attack when applied to 3D meshes as well. Replication of watermark provides robustness against localized noise addition, cropping, simplification and global noise addition attacks. Security of the scheme is analyzed, and the time complexity is estimated as O (n log n), where n is the number of 3D points. Theoretical bounds on hiding capacity are estimated, and experiments show that a high hiding capacity is high, with embedding rate greater than 3 bits/point. The bit encoding method reduces the distortions and makes the watermark imperceptible, indicated by a signal to noise ratio greater than 100 dB.
The paper proposes a digital watermarking algorithm for 2D vector digital maps. The watermark is a robust, informed-detection watermark to be used to prevent such abuses as an intellectual property rights violation. The algorithm proposed in the paper embeds watermarks in the frequency-domain representation of a 2D vector digital map. Our method treats vertices in the map as a point set, and imposes connectivity among the points by using Delaunay triangulation. The method then computes the mesh-spectral coefficients (Karni, 2000) from the mesh created. Modifications of the coefficients according to the message bits, and inverse transforming the coefficients back into the coordinate domain produces the watermarked map. Our evaluation experiments showed that the watermark produced by the method is resistant against additive random noise, similarity transformation, vertex insertion and removal. It is also resistant, to some extent, against cropping. Compared to our previous algorithm (Ohbuchi, 2002), the algorithm described in this paper showed significantly improved attack resiliency.
This paper summarises recent work in the area of point pattern matching and introduces a new approach to the more general problem of point pattern recognition. The new technique developed by the authors is invariant to rotational, scaling and translational transformations, and is optionally reflection invariant. The techniques presented are compared, and specific applications are described. 1 Introduction Point pattern analysis plays an important role in picture pattern recognition. It is often advantageous to represent sets of local features (e.g. corners) in an image by their coordinates. The coordinates can be used to identify patterns in the image, rather than matching pictures as arrays using techniques such as template matching. The use of point pattern matching (PPM) is most efficient relative to array processing techniques in situations where the size of the image is large and the number of feature points is low. The speed of point pattern techniques in such situations, their ...
Digital maps are used, for example, in car navigation systems and web-based map services. As digital data, digital maps are easy to update, duplicate, and distribute. At the same time, illegal duplication and distribution or forgery of the maps is also easy. This paper proposes a digital watermarking algorithm for vector digital maps as a method to counter such abuses of the maps. A watermark bit is embedded by displacing an average of coordinates of a set of vertices that lies in a rectangular area created on a map by adaptively subdividing the map. The watermark is resistant against additive random noise, similarity transformation, and vertex insertion/removal, and, to some extent, cropping.
The purpose of a countermeasure is to thwart an attack on hidden information. Depending upon the intent of the hidden information, countermeasures may be to make the hidden information more difficult to detect (typical for steganography) or more robust to distortion (typical for digital watermarks).
List of Figures. List of Tables. Preface. 1. Introduction. 2. Exploring Steganography. 3. Steganalysis: Attacks Against Hidden Data. 4. Counter Measures to Attacks. Appendix A: Hiding Data in Network Traffic. Appendix B: Glossary of Methods to Distort Stego-Images. References. Index.
A semi-fragile digital watermarking algorithm resisting affine transformation based on 2D vector graphics was designed for tamper localization. We divide graphics vertices after extraction, and then transform the construction of 8 × 8 matrix by DCT; authentication watermark is generated by the relationship between the DCT coefficients, and then embedded in the middle frequency region of the coefficients; pre-processing is proposed to eliminate geometric distortion before detecting. High invisibility, robust against common geometrical distortions (e.g. translation, rotation and scaling) and good capability of tamper localization have been proved by experimental results.
We present an explicit method to compute a generalization of the Fourier Transform on a mesh. It is well known that the eigenfunctions of the Laplace Beltrami operator (Manifold Harmonics) define a function basis allowing for such a transform. However, computing even just a few eigenvectors is out of reach for meshes with more than a few thousand vertices, and storing these eigenvectors is prohibitive for large meshes. To overcome these limitations, we propose a band-by-band spectrum computation algorithm and an out-of-core implementation that can compute thousands of eigenvectors for meshes with up to a million vertices. We also propose a limited-memory filtering algorithm, that does not need to store the eigenvectors. Using this latter algorithm, specific frequency bands can be filtered, without needing to compute the entire spectrum. Finally, we demonstrate some applications of our method to interactive convolution geometry filtering. These technical achievements are supported by a solid yet simple theoretic framework based on Discrete Exterior Calculus (DEC). In particular, the issues of symmetry and discretization of the operator are considered with great care.
This paper presents a reversible watermarking scheme for the 2D-vector data (point coordinates) which are popularly used in geographical information related applications. This reversible watermarking scheme exploits the high correlation among points in the same polygon in a map and achieves the reversibility of the whole scheme by an 8-point integer DCT, which ensures that the original 2D-vector data can be watermarked during the watermark embedding process and then perfectly restored during the watermark extraction process, with the watermark accurately extracted at the same time.In our scheme, we use an efficient highest frequency coefficient modification technique in the integer DCT domain to modulate the watermark bit "0" or "1", which can be determined during extraction without any additional information to indicate.To alleviate the visual distortion in the watermarked map caused by the coefficient modification, we propose an improved reversible watermarking scheme based on the original coefficient modification technique. Combined with this improved scheme, the embedding capacity can be greatly increased while the watermarking distortion is otherwise deduced compared to the original coefficient modification scheme.To control the distortion between the watermarked 2D-vector data and its original version, we design an error estimation method to prevent those data which are able to cause large distortions in the coefficient modification process from being watermarked. This distortion limitation scheme can fine adjust the watermarking distortion and capacity for the proposed coefficient modification based reversible watermarking scheme according to different practical requirements.
Abstract This paper presents a robust watermarking algorithm with informed detection for 3D polygonal meshes. The algorithm is based on our previous algorithm [ 22] that employs mesh-spectral analysis to modify mesh shapes in their transformed domain. This paper presents extensions to our previous algorithm so that (1) much larger meshes can be watermarked within a reasonable time, and that (2) the watermark is robust against connectivity alteration (e.g., mesh simplification), and that (3) the watermark is robust against attacks that combine similarity transformation with such other attacks as cropping, mesh simplification, and smoothing. Experiment showed that our new watermarks are resistant against mesh simplification and remeshing combined with resection, similarity transformation, and other operations..
This paper presents a robust watermarking algorithm with informed detection for 3D polygonal meshes. The algorithm is based on our previous algorithm [22] that employs mesh-spectral analysis to modify mesh shapes in their transformed domain. This paper presents extensions to our previous algorithm so that (1) much larger meshes can be watermarked within a reasonable time, and that (2) the watermark is robust against connectivity alteration (e.g., mesh simplification), and that (3) the watermark is robust against attacks that combine similarity transformation with such other attacks as cropping, mesh simplification, and smoothing. Experiment showed that our new watermarks are resistant against mesh simplification and remeshing combined with resection, similarity transformation, and other operations.. Keywords: geometric modeling, polygonal meshes, mesh spectral analysis, copyright protection, information hiding, steganography.
A blind watermarking method for the copyright protection of sets of polygonal lines in vector graphics images and GIS data (elevation contour maps) is presented. The paper focuses mainly on the use of simple fusion rules for combining the detector outputs from each polygonal line in order to come up with a global detection result. Experimental comparison of the various fusion methods using both synthetic and real data (elevation maps) is provided.
A method for watermarking of polygonal lines is proposed. The
watermark is embedded in the Fourier descriptors of the polygonal line
causing minor distortions to the coordinates of the vertices of the
polygonal line. Watermarks generated by this technique can be
successfully detected even after rotation, translation, scaling and
reflection of the host polygonal line