For the protection of Intellectual Property Rights (IPR), different passive protection methods have been developed. These watermarking and fingerprinting technologies protect content beyond access control and thus tracing illegal distributions as well as the identification of people who are responsible for a illegal distribution is possible. The public's attention was attracted especially to the second application by the illegal distribution of the so called 'Hollywood screeners'. The focus of current research is on audio and video content and images. These are the common content types we are faced with every day, and which mostly have a huge commercial value. Especially the illegal distribution of content that has not been officially published shows the potential commercial impact of illegal distributions. Content types, however, are not limited to audio, video and images. There is a range of other content types, which also deserve the development of passive protection technologies. For sheet music for instance, different watermarking technologies have been developed, which up to this point only function within certain limitations. This is the reason why we wanted to find out how to develop a fingerprinting or perceptual hashing method for sheet music. In this article, we describe the development of our algorithm for sheet music, which is based on simple graphical features. We describe the selection of these features and the subsequent processing steps. The resulting compact representation is analyzed and the first performance results are reported.
A fingerprinting is related to cryptographic hash functions. In contrast to cryptographic hash functions this robust digest is sensitive only to perceptual change. Minor changes, which are not affecting the perception, do not result in a different fingerprint. This technique is used in content-based retrieval, content monitoring, and content filtering. In this paper we present a cumulant-based image fingerprinting method. Cumulants are typically used in signal processing and image processing, e.g. for blind source separation or Independent Component Analysis (ICA). From an image with reduced dimensions we calculate cumulants as an initial feature vector. This feature vector is transformed into an image fingerprint. The theoretical advantages of cumulants are verified in experiments evaluating robustness (e.g. against operations like lossy compression, scaling and cropping) and discriminability. The results show an improved performance our method in comparison to existing methods.
We investigate in this paper several possible methods to improve the performance of the bit-shifting operation based reversible image watermarking algorithm in the integer DCT domain. In view of the large distortion caused by the modification of high-amplitude coefficients in the integer DCT domain, several coefficient selection methods are proposed to provide the coefficient modification process with some adaptability to match the coefficient amplitudes’ status of different 8-by-8 DCT coefficient blocks. The proposed adaptive modification methods include global coefficient-group distortion sorting, zero-tree DCT prediction, and a low frequency based coefficient prediction method for block classification. All these methods are supposed to optimize the bit-shifting based coefficient modification process so as to improve the watermarking performance in terms of capacity/distortion ratio. Comparisons are presented for these methods in aspects of performance in terms of capacity/distortion ratio, performance stability, performance scalability, algorithm complexity and security. Compared to our old integer DCT based scheme and other recently proposed reversible image watermarking algorithms, some of the proposed methods exhibit much improved performances, among which the low frequency based coefficient prediction methods bear highest efficiency to predict the coefficient amplitudes’ status, leading to distinct improved watermarking performance in most aspects. Detailed experimental results and performance analysis are also given for all the proposed algorithms and several other reversible watermarking algorithms.
We present a high capacity reversible watermarking scheme using companding technique over integer DCT
coefficients of image blocks. This scheme takes advantage of integer DCT coefficients' Laplacian-shape-like
distribution, which permits low distortion between the watermarked image and the original one caused by the bit-shift
operations of the companding technique in the embedding process.
In our scheme, we choose AC coefficients in the integer DCT domain for the bit-shift operation, and therefore the
capacity and the quality of the watermarked image can be adjusted by selecting different numbers of coefficients of
different frequencies. To prevent overflows and underflows in the spatial domain caused by modification of the DCT
coefficients, we design a block discrimination structure to find suitable blocks that can be used for embedding without
overflow or underflow problems. We can also use this block discrimination structure to embed an overhead of location
information of all blocks suitable for embedding. With this scheme, watermark bits can be embedded in the saved LSBs
of coefficient blocks, and retrieved correctly during extraction, while the original image can be restored perfectly.
Publishers of sheet music are generally reluctant in distributing their content via the Internet. Although online sheet music distribution's advantages are numerous the potential risk of Intellectual Property Rights (IPR) infringement, e.g. illegal online distributions, disables any innovation propensity.
While active protection techniques only deter external risk factors, additional technology is necessary to adequately treat further risk factors. For several media types including music scores watermarking technology has been developed, which ebeds information in data by suitable data modifications. Furthermore, fingerprinting or perceptual hasing methods have been developed and are being applied especially for audio. These methods allow the identification of content without prior modifications.
In this article we motivate the development of watermarking and fingerprinting technologies for sheet music. Outgoing from potential limitations of watermarking methods we explain why fingerprinting methods are important for sheet music and address potential applications. Finally we introduce a condept for fingerprinting of sheet music.
In this paper we present a new method for hiding data in music scores. In contrast to previous published algorithms we investigate the possibilities of embedding information in clefs. Using the clef as information carrier has two advantages: First, a clef is present in each staff line which guarantees a fixed capacity. Second, the clef defines the reference system for musical symbols and music containing symbols, e.g. the notes and the rests, are not degraded by
manipulations. Music scores must be robust against greyscale to binary conversion. As a consequence, the information is embedded by modifying the black and white distribution of pixels in certain areas. We evaluate simple image processing mechanisms based on erosion and dilation for embedding the information. For retrieving the watermark the b/w-distribution is extracted from the given clef. To solve the synchronization problem the watermarked clef is normalized in a pre-processing step. The normalization is based on moments. The areas used for watermarking are calculated by image segmentation techniques which consider the features of a clef. We analyze capacity and robustness of the proposed method using different parameters for our proposed method. This proposed method can be combined with other music score watermarking methods to increase the capacity of existing watermarking techniques.
Content protection for multimedia data is widely recognized especially for data types that are frequently distributed, sold or shared using the Internet. Particularly music industry dealing with audio files realized the necessity for content protection. Distribution of music sheets will face the same problems. Digital watermarking techniques provide a certain level of protection for these music sheets. But classical raster-oriented watermarking algorithms for images suffer several drawbacks when directly applied to image representations of music sheets. Therefore new solutions have been developed which are designed regarding the content of the music sheets. In Comparison to other media types the development for watermarking of music scores is a rather young art. The paper reviews the evolution of the early approaches and describes the current state of the art in the field.
A video watermarking with robustness against rotation, scaling and translation (RST) is proposed. The watermark information is embedded into pixels along the temporal axis within a Watermark Minimum Segment (WMS). Since the RST operations for every frame along the time axis in video sequence are the same at a very short interval, the watermark information can be detected from watermarked frames in each WMS subjected to RST. Experimental results show that the proposed technique is robust against the attacks of RST, bending and shearing of frames, MPEG-2 lossy compression, color-space conversion, and frame dropping attacks.
Current music score watermarking techniques either lack in robustness or in capacity: While embedding data into staff lines guarantees a certain payload, modulation of the staff lines' thickness can be attacked using image processing techniques. Changing properties of musical symbols is more robust. But, the number of musical symbols limits the payload. Therefore, we propose the following method: The staff lines' distances are used as a carrier signal for embedding information. Changes are applied by using an image warping technique to reduce artifacts. Image warping techniques can also be applied locally to music symbols to change their properties, e.g. their horizontal distance or their width. Thus, quality improves. Furthermore, musical symbols doesn't have to be recognized. It is sufficient to cluster the symbols according to their properties and to treat symbols of the same cluster equally. The described method guarantees a minimum payload and increased robust. The application of image warping techniques reduces visible distortion. The results are visual appealing music scores. Capacity improvement can be achieved by applying the proposed methods to music symbols.
The need for protection mechanisms for multimedia content is widely recognized. In the past digital watermarking algorithms for images have been developed that provide a certain level of protection for colored or gray-scale images. Since classical raster-oriented watermarking algorithms do not satisfy the needs for symbol oriented music score images we present in this paper a solution that should give promising robustness of the watermark at minimal visibility impact. This solution respects the content of binary images and can be considered as a symbolic interpretation and modification of music scores. Some music symbols are used by changing their features for hiding an information string in a music score. The advantage is its robustness and invisibility. Regarding the invisibility a musician should under no circumstances be impeded in reading the music. One must even consider the fact of being influenced unconsciously. For example, it might be more difficult to concentrate on a music sheet if the symbols were changed invisibly. The most probable way of distributing music scores is the analog (paper) form. Music scores are copied and distributed. So watermarks should be readable even after multiple copy procedures. By choosing suitable features a blind detection of the watermark is possible.