232 results about "Watermark algorithm" patented technology

The invention discloses a method for controlling the file access of GIS (geographical information system) vector data. The method comprises three technical links: the insertion of the copyright mark m into the GIS vector data file, the extraction of the copyright mark m and the data recovery, and the data application monitoring and the data access control, wherein, the copyright mark m is divided into copyright marks for indication and certification. When the GIS vector data products are published, an excessive amount of copyright marks are inserted into the published products by the reversible watermark algorithm and the data accuracy is intentionally reduced, therefore, on one hand, the application of data-sharing among subscribers for educational and general purposes can be supported by directly downloading the data, and on the other hand, the commercial use of data can be limited by reducing the data accuracy. When the data is applied among high-end subscribers for research and commercial purposes, the extraction of the copyright mark and the data recovery can be realized in a real-time and open manner by installing the monitoring program based on the filter driver technology, thereby not only realizing the copyright certification on a real-time basis and acquiring the original lossless data products, but also limiting the unauthorized operation of validated subscribers.

The invention discloses a multiple digital watermarking method for geographic information system (GIS) vector data, and belongs to the field of geographic information copyright protection. The watermark embedding process of the method comprises the following steps of: reading and processing the data; embedding algorithms by an odd-even method; respectively embedding watermarks into a spatial domain, a discrete wavelet transform domain, a discrete cosine transform domain of horizontal coordinates and vertical coordinates by a low-order additive method and a least significant bit substitution method; adopting a zero-watermark algorithm; and storing watermark-containing data. The watermark extraction process of the method is the inverse process of the embedding process. A practical multiple digital watermark protection method is comprehensively integrated aiming at the common attack modes of the GIS vector data and according to the principle and anti-attack performance of each single algorithm. Various embedding modes are adopted and the specific embedding position of each watermark is controlled, so that embedding and extraction are non-interfering, conflicts are avoided, the advantages of each algorithm are exerted and complemented and the anti-attack capability of digital watermarks is greatly improved.

The invention provides a reversible watermark method based on histogram shifting and has significant practical values for protecting multimedia copyrights. By means of the reversible watermark method, traditional histogram shifting algorithms are improved in two aspects, firstly, 1 and 0 in a bite map are more imbalanced by arranging a generation process of the bit map on watermark embedding rather than in a non-pretreatment stage, so that compression is easier, and embedding capacity is improved; and secondly, the reversible watermark method is a two-step embedding method. The watermark blind extraction is achieved and troubles that the histogram shifting method needs extra side information transmitting are solved by dividing an image into an upper large area and a lower large area, subjecting the upper area to the watermark embedding, embedding the generated side information into the lowest significant bit containing watermark pixels in the area, and embedding the left watermark information and the replaced lowest significant information into the lower area.

The invention discloses a high-capacity reversible watermark method based on predication and companding technique. Through the introduction of the companding technique, the invention includes two processes: watermark embedding and watermark extracting. The invention effectively solves the problem of capacity consumption of position drawing in reversible watermark algorithm, and achieves high embedding capacity even in the situation of low threshold value. Meanwhile, due to the operation of data re-embedding after the compression of high predication errors, the invention still can maintain high peak signal to noise ratio (PSNR value).

The invention discloses a wavelet domain color image watermark encryption algorithm based on differential evolution. The operating method comprises the following steps: performing color space transformation on an original image to obtain a YIQ color format suitable for a human vision system and extracting a brightness component Y; adopting Arnold scrambling on a watermark image; performing three-stage discrete wavelet decomposition on the component Y of the original image to generate four sub-bands of different frequencies by utilizing discrete wavelet transform, thereby obtaining a sub-band image; representing a sub-band image matrix by using A, and performing singular value decomposition on the image subjected to three-stage wavelet decomposition; performing primary discrete wavelet decomposition on the watermark image subjected to scrambling encryption processing; performing watermark embedding; adaptively optimizing and selecting embedding strength by adopting differential evolution, and adding watermark information into the original image subjected to singular value decomposition in a multiplicative addition form. The invention has the beneficial effects that the watermark algorithm has high invisibility and is high in robustness.

The invention provides a three-dimension mesh model copyright verification method, which comprises the following steps that S1, light holographical encryption copyright watermark information is generated; S2, a three-dimension mesh model is preprocessed; S3, a model geometrical characteristic matrix is built in a cylindrical coordinate system; S4, the geometrical characteristic matrix is subjected to QR decomposition to embed copyright watermark information; S5, the three-dimension mesh model embedded with the copyright watermark information is issued on public information platforms such as Internet; S6, the obtained three-dimension mesh model to be detected is subjected to pre-processing for carrying out QR decomposition on the geometrical characteristic matrix to extract a copyright encryption information grey-scale map, a copyright two-value watermark image is obtained through Fourier inversion and filtering by a two-order Butterworth high pass filter, and the copyright ownership of the three-dimension mesh model can be judged through human eye identification. The method belongs to an air space blind watermark algorithm, higher robustness is realized, and the obvious problems that the existing three-dimension mesh model copyright verification method can be easily cracked and copied, and the copyright anti-fake certification cannot be conveniently or effectively carried out are solved.

The invention discloses a robust image watermark new method based on a local Tchebichef moment, mainly solving the problem that a watermark arithmetic based on image characteristic at present can not effectively resist general image processing and geometry attack simultaneously. The method comprises the steps as follows: firstly, extracting characteristic points of an original image by utilizing a Harris-Laplace detection operator, and obtaining a group of stable and mutually independent round characteristic areas through characteristic selection; then obtaining a geometrically unchanged round characteristic area through principle direction alignment; and finally, calculating the Tchebichef moment in an inscribed square image block of the round characteristic area, and embedding a watermark through dithering quantized modulation to modify an amplitude value with low-level Tchebichef moment. In detection, the modified low-level Tchebichef moment is obtained through the dithering quantized modulation, and a minimum distance is utilized to realize the blind extraction of the watermark. The invention has favorable nonvisibility, excellent robust performance for general image processing, geometry attach and combined attach and superior performance to similar methods and can be used for copyright protection for different images.

The invention discloses a technical scheme of image digital watermark encryption, which comprises the following steps of: acquiring a public key and a private key by a user, wherein the public key is used for performing signature verification on any other person obtaining an image, and the private key is used for signing and sealing the image; signing the information contained in the image by using the private key to obtain signature information D, signing a combination of a hash value of a data area B of the image and public key information C by using the private key to obtain a signature result D, and finally immigrating the public key information C and the signature result D into the image; and extracting the public key information C and the signature result D embedded into the data area B of the image by a basic watermark algorithm, and verifying the public key information C and the signature result D. According to the method, an ID-based signature system of an ID-based public key encryption algorithm is adopted, so the public key information can have linguistic meaning, and the release problem of the public key is correspondingly well solved.

The invention provides an image digital watermark embedding method and an image digital watermark detecting method. The watermark embedding method comprises the following steps of: dividing a source image into a center circular block and a plurality of ring belt blocks, and transforming each set of data by a transform domain watermark algorithm and embedding the image digital watermark into the source image; and the watermark detecting method comprises the following steps of: carrying out a blocking step which is as the same as the embedding process on an image to be detected, transforming by the same transform domain watermark algorithm, and extracting and comparing the watermark. After the watermark embedding method and detecting method of the invention are adopted, the technical problem that the common image digital watermark is bad in attack robust performance resistance and small in watermark information capability in the prior art can be solved, the rotation with any angles can be resisted, the zooming with larger times can be resisted, the geometrical transformation attack with larger edge cutting can be resisted, and the methods are easily combined with the other digital watermark technologies, so that the non-geometric transformation attack such as the channel noise, the filtering and the lossy compression can be resisted.

The invention provides a method for embedding and extracting digital audio watermarks in a time domain on the basis of audio breakpoints, and an energy value of an original audio is directly changed on the basis of the original audio according to a numerical value of watermark information and the energy value of the original audio. Only little change is made on the basis of an original signal, and good robustness, cutting resistance and less information increase of watermarks are guaranteed on the premise that the hearing quality of the original audio is not influenced. In a watermark extraction link, the positions of the embedded watermarks can be automatically screened by an extraction algorithm, information which looks like watermarks in numerical logic is excluded, and the capability of storing original watermark information is provided. According to the method, the watermark information is encrypted. The used watermark extraction scheme is a blind watermark algorithm and can be used for processing audio signals, protecting audio products and the like, only fragmentation information of the original audio and reconstruction parameters of watermark signals are needed, and the participation of the original audio and original watermarks is not needed.

The invention provides a video dual watermark method based on SVD and QR codes. The method comprises the steps of watermark embedding and watermark extracting. Watermark embedding comprises the steps of Arnold scrambling, original video preprocessing, grayscale watermark embedding, reconstructing, grayscale watermark text information QR coding and QR code embedding. Watermark extracting comprises the steps that a key1 is used to acquire a watermark carrier image; mark extracting and Arnold inverse scrambling are carried out; a key2 is selected, and the image block of the QR code is hidden; and the QR code is decoded to acquire verification text information. According to the invention, embedded dual watermarks have the advantage of small mutual interference and good robustness for common attacks; the QR code information is embedded into the image block which is highly invisible; the safety of a video watermark algorithm is enhanced; and the problem of single function of a single robust watermark algorithm is effectively solved.

The invention discloses a general video digital watermark method mainly comprising analysis, embedding and extraction processes of a system design scheme. The analysis of the system design scheme comprises determination of a system function, watermark algorithms Ai to be embedded, embedding proportions of all algorithms and minimum extraction frame number Fmin; the watermark embedding process comprises frame distribution of a video file, watermark information pre-processing, embedding of watermark algorithms and formation of video files containing watermarks, wherein the embedding of watermark algorithms comprises the steps of: calculating embedding frame numbers, selecting embedding frames and embedding the watermark; and the watermark extracting process comprises frame distribution of the video file, selection of video frames to be detected, extraction of watermark information and calculation similarity. In the invention, the plurality of watermark algorithms are embedded at the same time and the embedding proportions can be selected, thereby the watermark method obviously enhances attack-resistant property; the watermark embedding ensures the appreciation and the embedding speed of the video file by using a non-frame-by-frame embedding way; in the watermark extracting process, the number of the detecting frames is less and the detection efficiency is improved; in addition, the general video digital watermark method also intensifies the capability of resisting frame edition.

The present invention belongs to the image signal processing field, in particular a self-adapting watermark algorithm of a color image supercomplex frequency domain. Fistly, the algorithm processes a quick supercomplex Fourier transform to color carrier image, selecting proper frequency band in the supercomplex frequency spectrum real component, masking the vein, edge and brightness of the color carrier image by the human visual system, bestowing different masking intensities to the selecting frequency bands to embed watermark, achieving a self-adapting watermark algorithm of a color image supercomplex space. The result shows that the self-adapting masking of the color image greatly improve non intangibity and safety of the supercomplex frequency domain watermark algorithm, and having better aggressivity than the supercomplex frequency domain watermark algorithm having non-self-adapting mask; contrast to the present documents, the advantages of the invention are verified.

The invention discloses a visual-saliency-based image non-watermark method and belongs to the technical field of information hiding. The visual saliency based image non-watermark algorithm is characterized by introducing a KochandItti visual attention mechanism model to automatically analyze and divide an image saliency region, executing SIFT (scale invariant feature transform) feature extraction on the image saliency region, further screening the extracted feature information, and registering the screened feature information as non-watermark information which identifies the image uniquely. The invention further discloses an image copyright authentication method based on the non-watermark algorithm. The algorithm has better robustness to synchronization attacks and regular image processing for moderate image geometric distortion, filtering, noise pollution and the like, thus providing a new way for protecting and authenticating copyright of digital images.

The invention discloses a three-dimensional geographic model digital watermark embedding and detection method, and belongs to the technical field of geographic information copyright protection. The method is based on that a texture coordinate value of three-dimensional geographic model data after an attack is changed without a variation in a data value of corresponding texture mapping. Thus, the method, on the basis of analysis of a previous watermark algorithm and by making full use of characteristics of texture mapping, re-establishes an embedding position of a watermark and builds a new digital watermarking model of the three-dimensional geographic model data. Not only is a three-dimensional grid data file of a three-dimensional geographic model embedded, but also a data file of the texture mapping is embedded with the watermark information. The problems are solved that a single geographic model algorithm is low in robustness for some attacks and that a current three-dimensional geographic model data file with texture mapping data cannot detect a watermark after a file attack and a model attack.

The invention discloses a feature invariant based remote sensing image watermark method which is directed at overcoming the incompatibility between anti-geometric attack and anti common image processing attack of the DCT algorithm and at the same time fully exhibits the advantages of 2D code, such as large storage information amount and strong error correction. The method includes the following steps: looking for invariants in 8 x 8 subblocks converted by the DCT algorithm, calculating embedded watermark information bits by using a mapping function in combination with the invariants, marking an initial position of each 8 x 8 subblock with intermediate frequency coefficients. In the process of watermark detection, image blocks containing watermark information can be located in a rapid and accurate manner through the determination of a feature location region. According to the invention, features of pixel digital numbers of remote sensing images before and after the geometric attack are fully utilized to address the problem of desynchrony of watermark information, which substantially increases robustness of the DCT algorithm, addresses the problem of inability of current remote sensing image digital watermark algorithm to resist cropping attacks, and effectively protects copyright of remote sensing image data.

The invention discloses a color image blind watermarking method. A color digital image is used as a digital watermark to be inserted in a color host image by utilizing Hessenberg matrix disintegration, and the inserted color image watermark is good in invisibility, so that the requirement for protecting a copyright based on a color image marker can be met. A 4*4 pixel block is disintegrated in a Hessenberg way, the encrypted color image digital watermark information is inserted into a maximum coefficient of the Hessenberg matrix by utilizing a coefficient quantization technology, the original host image or the original watermark image is not needed when the watermark is extracted, and a blind detection object can be realized. The method is good in watermark algorithm performance and suitable for the copyright protection adopting the color digital image as the digital watermark.

The invention mainly aims to solve the security attack problem of watermarks, and provides a high-security watermark algorithm by further referring to an encryption mechanism and a dual-watermark mechanism on the basis of making full use of a password thought and a theory of error-correcting codes specific to different security attack characteristics. In the algorithm, a watermark embedding link is partitioned into a private watermark embedding part and a public watermark embedding part. Private watermarks are embedded through an adaptive spatial domain watermark algorithm; original watermarks are encrypted by further referring to a carrier feature sequence on an information layer; error correction coding is performed on an encrypted sequence through Hamming error correcting coding in order to cope with copy attacks; and watermark embedding positions and embedding strengths are encrypted on a transmission layer in order to cope with homologous detection attacks. Public watermark embedding is finished through an adaptive watermark algorithm which has high robustness and is based on DCT (Discrete Cosine Transform), so that detection of collusion attacks can be realized. As proved by a test result, the problem of security attacks to the watermarks can be well solved.

The invention discloses an image retrieval method and system. The method comprises the steps that an original image is embedded after annotation information is encrypted into ciphertext data, and substituted original pixels are used as a watermark generation annotation image through a reversible watermarking algorithm; and the ciphertext data in the annotation image is extracted and decrypted, the decryption result is matched with retrieval conditions to acquire a target annotation image, a pixel value of the original image corresponding to the target annotation image is calculated, and a watermark is output after being extracted. The algorithm has a small influence on the original image, and the original image can be restored in one hundred percent at a receiving end; meanwhile, the algorithm is high in speed and adaptive to a large quantity of sample annotation scenes, so that space complexity is lowered; the encrypted annotation information is prevented from being tampered, and therefore the validity, relevancy and manageability of the annotation information are improved.

The invention discloses a digital watermark algorithm based on text document protection. Implementation of watermark information in a text document consists of watermark embedding and watermark extracting; a watermark embedding treatment process comprises carrier text image pretreatment, ciphertext ID coding, pseudo-random periodic sequence watermark generation and carrier image fusion; and the watermark extracting treatment process comprises image reinforced treatment, extraction of a pseudo-random sequence watermark texture map and decoding of watermark information. For solving the technicalproblem that an existing digital watermark algorithm is poor in robustness, required ID information can be embedded in a text document by the algorithm, and even if a watermarked text is copied, photographed and sheared and the geometric structure of the watermarked text is damaged, watermark information concealed in the watermarked text can still be detected. The digital watermark algorithm based on text document protection can be widely applied to protection and tracing of documents with secret, document copyright protection, web page copyright protection, image mark protection of some commercial products and the like.

The invention relates to a data tracing method and system based on a digital watermarking technology, and the method comprises the steps: employing a first watermark algorithm, embedding an initial watermark in an original data set, and obtaining an initial data set; E; embedding a transaction watermark into the initial data set to be delivered by utilizing a second watermark algorithm to obtain adelivery data set and delivering the delivery data set to a delivery object; J; judging whether initial watermarks exist in the to-be-traced data set or not, if yes, judging whether transaction watermarks corresponding to the identity information of the to-be-verified candidates exist in the to-be-traced data set or not, and confirming the to-be-verified candidates pointed by the to-be-traced data set according to a judgment result. According to the invention, t, the initial watermark and the transaction watermark are embedded into the data circulated by the data obligee; I; in the data rights protection stage, rights protection audit is conducted on a data obligee through an initial watermark, declaration of a membership right is achieved, t, then in the further data tracing stage, a delivery object pointed by a to-be-traced data set is confirmed through a transaction watermark, and therefore tracing of a leakage source is achieved.