35 results about "Quantization index modulation" patented technology

The invention discloses a video watermarking method based on a visual attention mechanism. Binary-system watermark information is embedded into a DCT domain in a visual non-saliency area of an MPEG-2 video key frame is selected to achieve the purpose of video copyright protection. The video watermarking method comprises the following steps of decoding a carrier video and obtaining the video key frame I; adopting a Koch and Itti visual remarkable model to analyze visual saliency of the video key frame and dividing a visual saliency area; selecting the visual non-saliency area human eyes are not too sensitive to, performing fixed-step-length odd-even quantization index modulation on a DCT direct current coefficient of luminance component and embedding watermark information; analyzing the visual saliency of the video key frame with embedded watermarks, judging a watermark embedding area and extracting the watermark information according to watermark embedding rules. The visual attention feature of the human eyes is effectively utilized in the video watermarking method, the invisibility of the video watermarks is improved, the video watermarking method has good robustness on common video attacks, and contradiction between the watermark invisibility and the robustness is effectively relieved.

A hybrid watermark insertion method includes the steps of dividing the digital image into a low frequency region and a high frequency region using an edge map of the digital image; inserting a watermark into the low frequency region of the image by employing a watermarking method using a human visual system (HVS); and inserting the watermark into the high frequency region of the image by employing a quantization index modulation (QIM) method. A hybrid watermark extraction method includes the steps of estimating a reference value used when inserting a watermark, and searching a maximum value of correlation coefficients in an image of the watermark image while changing the estimated reference value within a designated range, to thereby find out the watermark insertion method. Accordingly, the watermark insertion method can be easily identified, thereby enabling the watermark extraction in a more readily manner.

The invention relates to an information hiding method for linear prediction voice coding. The method includes the following steps: regarding all positions, at which embedment can be carried out through use of QIM, in a linear prediction voice bit stream as an information hiding space and representing the space with an array A; according to a needed security level, selecting an embedment rate; partitioning the array A so as to obtain a partitioning array; according to a p and the embedment rate, generating a Key and generating a to-be-embedded array B; partitioning the to-be-embedded array B so as to obtain minimum embedment units C; according to the Key, selecting an embedment mode in the minimum embedment units so as to obtain one or more to-be-embedded sequences, wherein each to-be-embedded sequence includes a plurality of embedment positions; and on the basis of the to-be-embedded sequences, realizing hiding of secret information through combination of matrix coding and a QIM (Quantization Index Modulation) method. The invention also provides an information extracting method corresponding to the information hiding method.

The present invention provides an anti-geometric attack Robust watermark method based on a stable circle. The method utilizing basic concept of the the second watermark technology, comprehensive considering the image character and watermark information, firstly determines a stable circle based on the CSS angular point detected by the multi-scale curvature product method, then divides sectors in the stable circle which reference point is centroid of the image, embeds in watermark in the time-space area by the QIM method. The invention not only resists the processing attack of the conventional signal, but alos resists geometrical attack such as rotation, zoom, parallel move and cutting, capable of effectively protecting copyright of the digital media.

The invention addresses the problem of scale degradations that may occur in watermarking schemes based on quantization index modulation (QIM). In accordance with the invention, the quantization step size (D) being employed by the embedder (11) and detector (21) is derived (12, 22) from a measurable characteristic parameter which has the property that, when the applied signal is scaled by a factor (a), it is scaled by substantially the same factor. In a preferred embodiment, said parameter is the square root of the energy of the signal (), and the quantization step is a predetermined fraction (a) thereof.

It is an adaptive expanding transform jitter modulation watermarking method. The expanding transform jitter modulation watermarking has the advantages both quantitative index modulation watermarking and spread spectrum communication system, and it has a good performance against attack. However, the original STDM method uses the fixed quantization step, which takes no account of human perceptual model, so its performance is greatly limited. The invention introduces a human perception model / signal quality evaluation method to the original STDM, used to measure the distortion introduced by watermarking and compute a weighted sequence, and the use of weighted plastic watermarking idea changes host signals, to make the local variable capacity of the host signal apply for the human perception system; re-designing the quantization step to meet the distortion conditions determined by un-perceptibility. Using the method described in the invention, the embedded watermark can fully use the local characteristics of carrier signal, adaptive design the quantization step, greatly enhance the watermark robustness, and at the same time achieve a good watermark un-perceptibility.

The invention discloses a color image watermark embedding and detecting method based on quaternion Legendre moment correction. First, the Legendre invariant theory for traditional gray images is extended to a quaternion level, and a quaternion Legendre moment invariant suitable for describing color image content is constructed; and then, a digital watermark is embedded into a low-frequency region of a discrete quaternion cosine transform domain by a quantization index modulation (QIM) method. During watermark detection, part of low-order quaternion Legendre moment invariants are selected as feature vectors to obtain a least squares support vector machine (LS-SVM) training model so as to improve the performance of a color image classifier. Simulation experiments show that the method has good imperceptibility, and has good robustness to conventional signal processing (especially for the color attack mode) and de-synchronization attack.

The invention discloses a digital image watermarking method based on the local index torque characteristic. Characteristic points of an original image are extracted and screened through brightness probability density gradient Harris-Laplace operators, and a screened characteristic point image is obtained; in the obtained characteristic point image, round areas with the characteristic points as circle centers are extended into square areas, and local characteristic areas are constructed and screened; the index toque of the obtained local characteristic area image is obtained through calculation, needed stable index toque is selected, the amplitude values of the index torque are modified with a quantization index modulation method, and watermarking information is embedded; the selected index torque is respectively reconstructed before or after the watermarking information is embedded, two reconstructed images are obtained and subjected to difference value calculation, the obtained difference values are overlaid into the local characteristic areas corresponding to the original image, and small images with watermarks are obtained; watermarking information is embedded into all the local characteristic areas.

The invention discloses a blind audio watermark implementing method based on logarithmic quantization index modulation, and belongs to the technical field of audio watermarks. The blind audio watermark implementing method is characterized by including sufficiently utilizing robustness of vector norms and imperceptibility of the logarithmic quantization index modulation based on mu-law companding; improving safety and robustness of a watermark by the aid of a chaos sequence encryption watermark image; converting the sectioned vector norms of wavelet approximate components into a transform domain via the mu-law companding; then embedding an encryption binary watermark image; and extracting the binary watermark image after the watermark is attacked. The audio watermark algorithm has the advantages of high volume, fine tone, imperceptibility and robustness and low complexity, the watermark still can be correctly extracted by the aid of the method under various watermark attack conditions, and accordingly amplitude attack can be effectively resisted by the method.

There is provided a method of detecting a watermark included in a signal by way of quantization index modulation (QIM). The signal with the embedded watermark may have been geometrically transformed (e.g. spatially or temporally scaled) prior to detection. In order to detect the watermark even in such case, the embedder imposes an autocorrelation structure onto the embedded watermark data, for example by tiling. Initially, the detector applies conventional QIM detection. This step yields a first symbol vector, which corresponds to the embedded data when the signal was not tampered with, but does not correspond to the embedded data when the signal was subject to scaling. For example, when one data bit is embedded in each pixel of an image, 50% upsampling of the image causes a QIM detector to retrieve 3 data bits out of 3 received pixels, that is 3 data bits out of 2 original image pixels. Surprisingly, the autocorrelation of the first symbol vector will give a peak for a particular geometric transformation (e.g. the particular scaling factor). In accordance with the invention, the detector calculates said autocorrelation function, and uses the result to apply the inverse of the transformation, i.e. undo the scaling. A second pass of the conventional QIM detection will subsequently receive the embedded data.

The invention provides an iterative self-adapting quantitative index modulation watermarking method basing on a visual model, which includes the following steps: (1) to a specific value to be quantified, the quantization step is determined through a Watson visual model and varies with the varieties of the value to be quantified; (2) the quantization step is adopted, and a quantitative index modulation algorithm is used for embedding a watermark; (3) an iterative embedding process is added in the watermark embedding process, the watermark is detected after every bit is embedded. If the embedding is detected to be failed, the bit is embedded again. And if the embedding is detected to be successful, the embedding of a next bit is started. The iterative self-adapting quantitative index modulation watermarking method basing on a visual model determines the quantization step through the Watson visual model, eliminates the watermark extraction error of the watermark embedding detection caused by the inconsistency of the quantization step, which is provided with better robustness, can enhance the strength of the watermark under the condition of guaranteeing the invisibility of the watermark and guarantees the accurate detection of the watermark through the iterative embedding method. The watermark embedding process is shown as Figure 1.

The invention provides an anti-fake method for digital print. The method includes the steps of: a) at a built-in end, processing carrier images, fixing special corners and coordinates thereof, then generating a binary form of digital watermark information, and using quantization index modulation for watermark embedding; b) at a detecting end, transforming images such as registration and interpolation, then detecting to acquire information, and processing the information for statistical decision. The anti-fake method for digital print is capable of resisting noise and geometric transformations of print, and being widely used in the printing field.

The invention provides a method for embedding a watermark in a video. The method comprises the following steps of extracting more than one video frame from the video, and performing the following treatment on each extracted video frame X, wherein the treatment comprises the steps of performing singular value decomposition X=UsigmaVT to obtain a singular value matrix sigma=diag(sigma 1, sigma 2,ellipsis sigma n), wherein U and V are two unitary matrixes; grouping the singular values sigma 1, sigma 2, ellipsis sigma n in the singular value matrix; performing quantitative index modulation on the grouped singular values to obtain a singular value matrix sigma` embedded with the watermark; performing singular value decomposition inverse process X`=Usigma`VT on the singular value matrix sigma` embedded with the water mark to obtain a video frame X` embedded with the water mark; processing the more than one video frame to obtain more than one video frame X` and combining into the video embedded with the water mark. The method for embedding the watermark enables the video embedded with the watermark to achieve better video quality.

The invention discloses an angle quantification index modulation image watermarking method based on a compressed sensing technology. A chaotic sequence is adopted to construct a sparse random measurement matrix as an observation matrix, and a compressed sensing technology and an angle quantification index modulation algorithm are utilized to safely and snugly embed watermark information into a compressed sensing domain of a carrier image. The invention also provides an angle quantification index modulation image watermarking system based on a compressed sensing technology. The system includesan observation matrix constructing module, a watermark embedding module, an information transmission module and a watermark extracting module. According to the angle quantification index modulation image watermarking method and system based on a compressed sensing technology, the watermark information is embedded into the compressed sensing domain of the carrier image through the angle quantification index modulation algorithm at a sending end, related information of the observation matrix and the embedding position of the watermark serve as a key to be sent to a receiving end, watermark extraction is realized, the advantages of good concealing property, high security and the like are achieved, and very high robustness is shown when conventional watermark attacks such as noise, filtering,image compression, amplitude scaling and the like are resisted.

With quantisation index modulation QIM it is possible to achieve a very high data rate, and the capacity of the watermark transmission is mostly independent of the characteristics of the original audio signal, but the audio quality suffers from degradation with each watermark embedding-and-removal step. In order to avoid degradation of the audio quality, the inventive audio signal watermarking uses specific quantiser curves in time domain and in particular in frequency domain for embedding the watermark message into the audio signal, whereby the processing is almost perfectly reversible. Furthermore, it has embedded a power constraint in order to guarantee that the modifications of the audio signal due to the watermark embedding are inaudible.

VoIP (Voice over Internet Protocol) serving as the Internet communication technology has a huge risk in privacy disclosure. In order to solve the problem of privacy disclosure in VoIP, the voice information hiding technology is gradually applied in the VoIP. The invention proposes a voice information hiding algorithm for a dynamic codebook based on complete binary tree grouping, and the method combines the dynamic codebook of iLBC and the QIM (Quantization Index Modulation) principles, and employs a complete binary tree for the grouping of the dynamic codebook. The algorithm comprises the steps that a transmitter selects a corresponding codebook for coding according to a secret information bit, and achieves the embedding of the secret information; a receiver completes the extraction of the secret information according to the attributes of a codon vector. A development and testing platform is built in a local area network, and the performances (hiding capacity, hiding performance, robustness and processing time delay) of the algorithm are estimated, which indicates that the algorithm is larger in capacity, is higher in hiding performance, is good in robustness, and is short in processing time.

The invention relates to an improved spread transform dither modulation (STDM) watermarking method and belongs to the technical field of digital watermarks. STDM watermarking has the combined advantages of quantization index modulation watermarking and a spread spectrum communication system, and high large watermark capacity and high robustness and has the disadvantage of high sensitivity to amplitude scaling attack. The invention constructs a signal invariable relative to the scaling for quantification by using a method which comprises: extracting from original content a statistical characteristic sequence which has a characteristic of scaling with original data according to the same scale factor; and obtaining the signal invariable relative to the amplitude scaling by dividing a carrier signal by the introduced characteristic sequence correspondingly. Watermark embedment and detection operation are both carried out on the newly constructed signal. The method improves the robustness of watermarks to amplitude scaling greatly and obtains watermarking performance similar to the original STDM watermarking in other aspects.

The invention discloses a vector geospatial data digital watermark method based on DFT coefficient combination. The method comprises steps that the watermark information is generated; a map is taken as an object, and a watermark carrier model is established based on the DFT coefficient combination polynomial; the map object is taken as a unit, the watermark information is modulated into each map object based on the established watermark carrier model; the watermark information is extracted for verification. The method is advantaged in that based on the DFT coefficient combination polynomial ofa geometric object feature point set, the classical quantization index modulation method is utilized to modulate the watermark information into each DFT coefficient of the polynomial, so watermark intensity is distributed to multiple coefficients, without reducing robustness of the algorithm, watermark invisibility is effectively improved, and the high fidelity of the data is achieved.

The present invention provides an anti-geometric attack Robust watermark method based on a stable circle. The method utilizing basic concept of the the second watermark technology, comprehensive considering the image character and watermark information, firstly determines a stable circle based on the CSS angular point detected by the multi-scale curvature product method, then divides sectors in the stable circle which reference point is centroid of the image, embeds in watermark in the time-space area by the QIM method. The invention not only resists the processing attack of the conventional signal, but alos resists geometrical attack such as rotation, zoom, parallel move and cutting, capable of effectively protecting copyright of the digital media.

The invention discloses a lattice theory based minimum distortion information hiding method and system and a medium. The method comprises the following steps of: obtaining a carrier signal vector, an embedded message and a group of nested lattices in an N-dimensional space through data initialization; calculating a lattice point closest to the carrier signal vector according to different secret information; calculating the difference value between the grid point and the carrier signal vector, and determining the position of the carrier information after the information is embedded; embedding a to-be-embedded message into the carrier signal vector and transmitting the to-be-embedded message; and extracting the secret information from the secret-containing carrier. According to the method, the carrier signal is moved into the Voronoi region of the lattice point in a minimum distance manner, so that the distortion caused by embedding is minimum while the embedding rate which is the same as that of quantization index modulation can be ensured, and the method is suitable for application scenes which have low requirements on robustness and pursue low distortion. In addition, according to the method, the movement distance is calculated by moving to the Packing space boundary of the grid point and utilizing the Packing radius, so that the calculation amount is saved, and the method has relatively high calculation efficiency.

The invention discloses a digital watermark processing method and device, electronic equipment and a storage medium. The digital watermark processing method comprises the steps of obtaining a to-be-embedded image; extracting face regions of the to-be-embedded image and splicing to obtain a digital watermark image; segmenting the to-be-embedded image of the preset channel of the YCbCr color space into a plurality of first image blocks with preset sizes; and based on a jitter quantization index modulation algorithm, performing quantization embedding processing on the coefficient in the first image block by using the digital watermark image to obtain an image embedded with the digital watermark in the RGB color space. According to the invention, the QIM-DM algorithm and the digital watermarkimage are used for jointly carrying out quantitative embedding processing on the coefficient in the first image block to obtain the image embedded with the digital watermark; by adding the digital watermark image which is not easily perceived by a human vision system into the image to be embedded, malicious attacks of a deep counterfeiting technology on the image or a video file are defended, theeffectiveness of a final detection result can be improved, and the accuracy of the final detection result is improved.

The invention relates to an improved spread transform dither modulation (STDM) watermarking method and belongs to the technical field of digital watermarks. STDM watermarking has the combined advantages of quantization index modulation watermarking and a spread spectrum communication system, and high large watermark capacity and high robustness and has the disadvantage of high sensitivity to amplitude scaling attack. The invention constructs a signal invariable relative to the scaling for quantification by using a method which comprises: extracting from original content a statistical characteristic sequence which has a characteristic of scaling with original data according to the same scale factor; and obtaining the signal invariable relative to the amplitude scaling by dividing a carrier signal by the introduced characteristic sequence correspondingly. Watermark embedment and detection operation are both carried out on the newly constructed signal. The method improves the robustness of watermarks to amplitude scaling greatly and obtains watermarking performance similar to the original STDM watermarking in other aspects.

There is provided a method of detecting a watermark included in a signal by way of quantization index modulation (QIM). The signal with the embedded watermark may have been geometrically transformed (e.g. spatially or temporally scaled) prior to detection. In order to detect the watermark even in such case, the embedder imposes an autocorrelation structure onto the embedded watermark data, for example by tiling. Initially, the detector applies conventional QIM detection. This step yields a first symbol vector, which corresponds to the embedded data when the signal was not tampered with, but does not correspond to the embedded data when the signal was subject to scaling. For example, when one data bit is embedded in each pixel of an image, 50% upsampling of the image causes a QIM detector to retrieve 3 data bits out of 3 received pixels, that is 3 data bits out of 2 original image pixels. Surprisingly, the autocorrelation of the first symbol vector will give a peak for a particular geometric transformation (e.g. the particular scaling factor). In accordance with the invention, the detector calculates said autocorrelation iunction, and uses the result to apply the inverse of the transformation, i.e. undo the scaling. A second pass of the conventional QIM detection will subsequently receive the embedded data.

The invention provides an iterative self-adapting quantitative index modulation watermarking method basing on a visual model, which includes the following steps: (1) to a specific value to be quantified, the quantization step is determined through a Watson visual model and varies with the varieties of the value to be quantified; (2) the quantization step is adopted, and a quantitative index modulation algorithm is used for embedding a watermark; (3) an iterative embedding process is added in the watermark embedding process, the watermark is detected after every bit is embedded. If the embedding is detected to be failed, the bit is embedded again. And if the embedding is detected to be successful, the embedding of a next bit is started. The iterative self-adapting quantitative index modulation watermarking method basing on a visual model determines the quantization step through the Watson visual model, eliminates the watermark extraction error of the watermark embedding detection caused by the inconsistency of the quantization step, which is provided with better robustness, can enhance the strength of the watermark under the condition of guaranteeing the invisibility of the watermark and guarantees the accurate detection of the watermark through the iterative embedding method. The watermark embedding process is shown as Figure 1.

The invention provides an anti-fake method for digital print. The method includes the steps of: a) at a built-in end, processing carrier images, fixing special corners and coordinates thereof, then generating a binary form of digital watermark information, and using quantization index modulation for watermark embedding; b) at a detecting end, transforming images such as registration and interpolation, then detecting to acquire information, and processing the information for statistical decision. The anti-fake method for digital print is capable of resisting noise and geometric transformations of print, and being widely used in the printing field.

The invention provides a tactile digital watermark embedding and detecting method based on electrostatic force, and belongs to the field of information security. The method includes: carrying out Edgedetection and texture extraction on an original picture and a user-defined vector diagram respectively; obtaining an original picture edge texture tactile feature and a user-defined vector diagram texture tactile feature through texture extraction, carrying out DES encryption fusion on the two features to obtain a tactile digital watermark, and embedding the tactile digital watermark into the original picture by using a quantitative index modulation algorithm; The method comprises the following steps: at a detection end, extracting a watermark, performing DES decryption separation on the watermark to obtain an original picture edge texture tactile feature and a user-defined vector diagram texture tactile feature, performing tactile modeling and rendering on the two parts respectively, re-superposing the two parts together, and inputting the two parts into an electrostatic force tactile terminal to realize tactile reproduction. According to the method, the digital watermark is embeddedand detected by additionally providing a tactile dimension, so that the anti-counterfeiting performance of the digital watermark is greatly improved, and the applicability and the safety of the watermark are enhanced.