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113results about How to "Improve invisibility" patented technology

Compressive-sensing-based digital image watermark embedding and extraction method

The invention discloses a compressive-sensing-based digital image watermark embedding and extraction method, and belongs to the technical fields of information hiding and image processing. The method comprises the following steps of performing sparsification processing on binary digital image watermark information to obtain sparse one-dimensional watermark information, and constructing a measurement matrix which is used as a key; measuring the one-dimensional watermark information to realize the compression and the encryption of the one-dimensional watermark information by using the key; performing discrete cosine transform on original carrier image information, blocking the transformed discrete cosine transform-domain information, and embedding the processed watermark information into a carrier image to obtain a watermark-containing image. According to the method, a compressive sensing method is used for processing watermarks, so that dual functions of watermark compression and encryption are realized, the number of the embedded watermarks is increased, the invisibility and the security are enhanced, and the overall performance of the watermarks is remarkably improved; an SBHE (scrambled block hadamard ensemble) matrix is applied, so that the method is small in memory space, high in calculation speed and simple in hardware; sparsity is introduced into a compressive sensing reconstruction process, so that the reconstruction accuracy and effects are greatly improved.
Owner:NORTHEASTERN UNIV

Video watermarking method based on visual attention mechanism

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.
Owner:HOHAI UNIV

Image watermark embedding method and extraction method, and related methods

The present invention discloses an image watermark embedding method, an image watermark extraction method, a digital media copyright protection method and a digital media copyright tracing method. The image watermark embedding method comprises: converting a watermark into a watermark binary sequence as required; carrying out a key-based spread spectrum operation on the watermark binary sequence, so as to determine a spread spectrum watermark vector; carrying out adaptive segmentation on a to-be-watermarked image; based on the adaptive segmentation, carrying out multistage discrete cosine transform on the to-be-watermarked image, so as to determine a first transform coefficient matrix; based on the first transform coefficient matrix, constructing a feature vector, and embedding the spread spectrum watermark vector into the feature vector; and carrying out coefficient reset, inverse discrete cosine transform of the coefficient matrix, and the like on the feature vector embedded with the spread spectrum watermark vector, so as to determine the watermarked image. According to the methods disclosed by the embodiments of the present invention, invisibility, robustness and security of the watermark are improved, and risk that the watermark is recognized and erased maliciously is weakened.
Owner:INST OF AUTOMATION CHINESE ACAD OF SCI

Text image watermark embedding method, text image watermark embedding system, text image watermark extracting method and text image watermark extracting system

ActiveCN110084733AReduce the risk of being identified and maliciously wipedImprove accuracyDigital data protectionImage data processing detailsPattern recognitionIntermediate frequency
The invention provides a text image watermark embedding method and system, and a text image watermark extraction method and system, and the text image watermark embedding method comprises the steps: carrying out the secondary encryption of an input watermark, and obtaining a watermark to be embedded through error correction coding; performing secondary discrete wavelet transform on the text imageto obtain four first frequency band coefficient matrixes; performing block discrete cosine transform on the first frequency band coefficient matrix to obtain a corresponding first block coefficient matrix; for each first block coefficient matrix, selecting an intermediate frequency coefficient, and embedding a watermark by modifying the coefficient to obtain each first block coefficient matrix embedded with the watermark; and performing inverse discrete cosine transform and inverse discrete wavelet transform on each first block coefficient matrix embedded with the watermark to obtain a text image embedded with the watermark. According to the embodiment of the invention, on the premise that the invisibility of the watermark is ensured, the robustness of the watermark for resisting attacks such as compression, noise and shearing and the algorithm security are improved.
Owner:INST OF AUTOMATION CHINESE ACAD OF SCI

Video watermark embedding method and video watermark extracting method

The invention discloses a video watermark embedding method and a video watermark extracting method, wherein the video watermark embedding method comprises the steps as follows: magnifying at a small scale a selected video frame image requiring watermark embedding and conducting self-adaption segmentation processing on a macro block and a subblock; selecting a transformation coefficient and embedding a watermark based on singular value decomposition (SVD) of the subblock and discrete cosine transformation (DCT) of the macro block; reconstructing the video frame image through inverse discrete cosine transformation, inverse process of singular value decomposition and small-scale shrinkage of the image. The video watermark extracting method corresponds to the embedding method, and the watermark extracted from a video frame is subjected to a series of post-processing to obtain a final watermark sequence. The methods provided by the invention have good universality, the video frame for watermark embedding and the selection of the transformation coefficient improve the invisibility and the robustness of the watermark, and the watermark embedding and extracting efficiencies are improved while the attacks against transcoding, noises, frame insertion, frame deletion, resolution change and the like are resisted.
Owner:INST OF AUTOMATION CHINESE ACAD OF SCI +1

H.264/AVC compressed-domain video watermark embedding and extracting method

The invention discloses an H.264 / AVC compressed-domain video watermark embedding and extracting method. Binaryzation is conducted on watermark images, and binary watermark information is obtained through Arnold transformation; compressed encoding is conducted on original video by using an H.264 / AVC encoder, 16 4*4 luminance blocks of each macro block are extracted out according to the H.264 / AVC video encoding standard, and integer discrete cosine transformation is conducted on each 4*4 luminance block; according to the coefficient of each 4*4 luminance block obtained after integer discrete cosine transformation, each 4*4 luminance block is divided into a texture block body and a non-texture block body; according to the binary watermark information, the local energy difference of each macro block is modulated; entropy encoding is conducted on the 4*4 luminance blocks obtained after binary watermarks are embedded to obtain video streaming with the watermarks. According to the H.264 / AVC compressed-domain video watermark embedding and extracting method, video information (texture and energy) is fully considered, and the robustness and invisibility of the watermarks are improved; operational complexity is low, no complex parameter choice exists, and higher real-time performance is achieved; the original video is not needed in the watermark extraction, and the H.264 / AVC compressed-domain video watermark embedding and extracting method belongs to a blind watermarking method.
Owner:CHINA ELECTRONIC TECH GRP CORP NO 38 RES INST +1

Embedding method and detection method for video digital hidden information

The invention discloses an embedding method and a detection method for video digital hidden information. The embedding method comprises the steps of: selecting an original video frame image to be embedded with digital hidden information from an original video; converting the digital hidden information to be embedded into a hidden information binary image; performing block DCT (Discrete Cosine Transform) on the original video frame image; modifying an intermediate frequency coefficient of each image sub-block after DCT according to the pixels corresponding to each image sub-block in the hiddeninformation binary image to embed the digital hidden information; performing block inverse discrete cosine transform on the modified DCT coefficients to obtain a video frame image embedded with the digital hidden information; and replacing the original video frame image in the original video with the video frame image embedded with the digital hidden information. The detection method comprises thesteps of: selecting the video frame image embedded with the digital hidden information and a previous frame of image from the video and subtracting the both directly to obtain a difference image; andsuccessively performing down-sampling and binarization on the difference image to obtain a hidden information binary image.
Owner:SHENZHEN GRADUATE SCHOOL TSINGHUA UNIV

Multi-form instant information hiding communication method and system based on image medium

ActiveCN105162686ALarge information embedding capacityHigh average data embedding efficiencyData switching networksData transmissionData conversion
The invention relates to a multi-form instant information hiding communication method and system based on an image medium. The system comprises a data conversion module, an encryption module, an information hiding module, a data transmission module, an information extraction module and an API interface. The data conversion module converts multi-form information (such as texts, voices or images) into binary data suitable for hiding; the encryption module is used for generating an information hiding secret key; the information hiding module is used for efficiently embedding the information after the encryption processing into a JPEG image. The data transmission module is responsible for carrier data safe transmission and cross-platform sharing functions. The information extraction module is characterized in that in an information hiding reverse process, the information hidden in the image can be seen only by inputting an encrypted password. An API provides the flexible interface to a user for calling system functions. According to the invention, the complete multi-form instant information hiding core algorithm and communication solution scheme based on the image medium are provided, and the method and the system provided by the invention have important theory and application values.
Owner:FUJIAN NORCA TECH

Remote-sensing image digital watermark embedding and extracting method based on quaternary wavelet

InactiveCN107292806AOvercoming translation sensitivityOvercoming Poor DirectionalityImage data processing detailsWavelet decompositionTucker decomposition
The invention discloses a remote-sensing image digital watermark embedding and extracting method based on the quaternary wavelet. The embedding process comprises carrying out quaternary wavelet decomposition on R, G and B wave bands of an original color remote-sensing image, making amplitude low frequency coefficients in the three wave bands form a third-order tensor, and then carrying out Tucker decomposition to obtain a core tensor; carrying out Arnold scrambling transformation on an original watermark image; embedding the scrambled watermark information into the core tensor, reconstructing the tensor and carrying out quaternary wavelet inverse transformation, and obtaining a color remote-sensing image including a watermark. The extracting process comprises carrying out quaternary wavelet decomposition on R, G and B wave bands of the color remote-sensing image including the watermark, making amplitude low frequency coefficients in the three wave bands form a third-order tensor, and then carrying out Tucker decomposition to obtain a core tensor; calculating the singular value of the core tensor to extract embedding information; and obtaining watermark information by means of inverse transformation of the Arnold scrambling transformation. According to the invention, invisibility and anti-attack capability of the watermark can be improved.
Owner:NANJING NORMAL UNIVERSITY

Wavelet-domain video watermarking method based on fractal theory

The invention relates to the technical field of processing of video images, and in particular relates to a wavelet-domain video watermarking method based on a fractal theory. In a watermark embedding process, firstly, wavelet transform of extracted key frames and watermark images is respectively carried out simultaneously; furthermore, decomposition of a wavelet tree D and a wavelet tree R is carried out; and then, direct multiplication by a strength coefficient is correspondingly embedded therein. According to the wavelet-domain video watermarking method based on the fractal theory disclosed by the invention, a method for embedding a watermark into a video is provided; therefore, the copyright of the video can be effectively protected; the problems of high video capacity, high calculation complexity and difficult watermark embedding can be solved; the watermark is embedded into the video through the method provided by the invention; the calculation amount is low; the consumed time is short; the quality of a video file cannot be influenced; the video after the watermark is embedded is high in invisibility and high in availability and robustness; and the method disclosed by the invention has a very important meaning for protecting the copyright of the video.
Owner:QINGDAO UNIV OF SCI & TECH

Authentication method of three-dimensional model file based on secret sharing in cloud environment

The invention provides an authentication method for a three-dimensional model file based on secret sharing in a cloud environment, which comprises the following steps of constructing a secret polynomial by adopting a Lagrange interpolation polynomial, generating the secret fragments from a source file, and transmitting and storing the secret fragments in a plurality of secret participants in a distributed manner; taking the source file and the secret fragments as the original structure carriers, respectively generating the digital abstracts from the secret fragments of the source file by utilizing an SM3 hash algorithm, and uploading the digital abstracts generated by the secret fragments to a cloud in a distributed manner; and recovering the digital digest of the three-dimensional model file based on a (k, n) threshold secret sharing method of Shamir, and performing consistency verification on the digital digest of the three-dimensional model file before encryption and after recovery.The invisibility, robustness and analysis resistance of the method are improved, and the fraudulent behaviors during the secret sharing process are effectively prevented. The method has the good performance at the aspect of protecting the integrity of the file, and particularly has the obvious advantages at the aspect of efficiency.
Owner:ZHENGZHOU UNIVERSITY OF LIGHT INDUSTRY

Pod-type water spraying propeller

InactiveCN107244405AStrong anti-cavitation abilityReduce vibrationPropulsive elementsPump-jetPropulsive efficiency
The invention provides a pod-type water jet propulsion unit, which comprises an installation platform, a pod propeller bracket arranged at the lower end of the installation platform, a pod propeller cabin body arranged at the lower end of the pod propeller bracket, a pod propeller cabin body arranged at the pod propulsion The motor base in the cabin body, the motor installed on the motor base, the transmission shaft connected to the output end of the motor, the water jet propulsion pump installed on the transmission axis, the lower end of the pod propeller cabin is provided with an inlet, a side A spout is provided, a flow channel is formed between the inlet and the spout, and the spout is set facing the water jet propulsion pump, and the upper end of the installation platform is provided with a data transmitter and a hydraulic steering device. The present invention is on the basis of maintaining the advantages of the original water jet propeller, adding the bracket, cabin body, electric propulsion system and steering device of the pod propeller, thereby reducing the complicated mechanical transmission mechanism and reversing device of the water jet propeller, further The propulsion efficiency and operational performance of the thrusters are improved, the noise is reduced and the stealth performance is enhanced.
Owner:HARBIN ENG UNIV

Anti-printing and scanning watermark algorithm for two-value text image based on row space and word space

The invention discloses a new blind watermark algorithm for a two-value text image, which mainly solves the problems of low watermark embedding capacity, non-blind extraction mode, easy discovery and the like in traditional word shift coding and row shift coding. The watermark algorithm of the invention comprises the realizing steps of: respectively extracting row space and word space in the two-value text image; respectively forming a one-dimensional row space vector and a word space vector by using a row as a main sequence; performing the operation of scrambling, blocking, modulating and inverse scrambling respectively on the row space vector and the word space vector in a watermark embedding process; finally, modifying the size of the row/word space of the two-value text image; and obtaining watermark information for embedding the two-value text image only by respectively performing the operation of scrambling, blocking and demodulation on the row space vector and the word space vector when extracting a watermark. The algorithm enhances the watermark embedding capacity on the premise that high invisibility and strong robustness of the watermark are ensured compared with the traditional word shift coding and row shift coding; and moreover, the embedded watermark information is robust for printing, duplication and scanning channels.
Owner:XIDIAN UNIV

Active imaging type infrared stealth system

The present invention discloses an active imaging type infrared stealth system. The active imaging type infrared stealth system is composed of a thermal imaging system, an image acquisition processing system, an infrared LED drive circuit and an infrared LED display system. The main characteristics of the present invention are that the infrared LED display system is arranged in various directions of the stealth system regionally, the image acquisition processing system acquires a background infrared image generated by the thermal imaging system, at the same time, transforms a background gray level image into a modulation pulse width image according to the corresponding correlation of the modulation pulse width of an infrared LED and an image gray level, and then zooms and segments the image to form the segmentation data blocks corresponding to the number of the display sub-units and send the segmentation data blocks to the infrared LED drive circuit, and the infrared LED drive circuit controls the infrared LED display system to display the background, so that the infrared characteristics of the stealth system in a hostile infrared system are similar to the background, and accordingly, the stealth purpose is achieved. The active imaging type infrared stealth system of the present invention has the advantages of being high in camouflage fidelity, fast in stealth speed and simple in structure, being easy to install and disassemble, etc.
Owner:西安应用光学研究所
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