41 results about "Embedding distortion" patented technology

A lossless, reversible data embedding technique uses a generalization of least-significant-bit modification. The portions of the signal that are susceptible to embedding distortion are compressed and sent as part of the embedded payload. A prediction-based conditional entropy coder uses unaltered portions of the host signal to improve lossless data capacity.

The invention provides a reversible information hiding method based on self-adaptive expansion of a two-dimensional prediction error histogram, and the method comprises the steps: dividing an originalimage into a black pixel layer and a white pixel layer in a checkerboard mode, and sequentially carrying out the following steps on the black pixel layer and the white pixel layer; pairing the adjacent pixels in the same layer of pixels, predicting pixel values, and obtaining a two-dimensional prediction error histogram; searching an optimal reversible mapping strategy through an adaptive optimization method according to the two-dimensional prediction error histogram; and performing secret information embedding on the image according to the optimal reversible mapping strategy. According to the method, the optimal reversible mapping strategy is found out in a self-adaptive optimization mode, on the premise that the embedding capacity is guaranteed, embedding distortion is reduced, and theembedding performance is improved.

The invention discloses an image steganography method and system for automatically learning distortion based on a GAN network structure, and the method comprises the steps: inputting an enhanced carrier image into a preset improved U-Net network, sequentially generating an initial pixel change probability graph and an initial secret-containing image, inputting the initial secret-containing image into a discrimination network, and obtaining a discrimination result, calculating the loss of the discrimination network according to the discrimination result, calculating a total loss function of the generative network according to the discrimination result and the current steganography capacity, optimizing the generative adversarial network by taking minimization of the loss function as a target, when the loss is reduced and kept stable, considering that the training is ended, extracting the generative network from the generative adversarial network after the training is ended, and inputting a to-be-transmitted original image into the generative network to obtain a pixel change probability, calculating embedded distortion corresponding to the pixel change probability, and coding the secret information and the to-be-transmitted original image by adopting a syndrome matrix coding technology according to the embedded distortion to obtain a steganographic image corresponding to the original image.

The invention discloses a high-volume reversible watermarking method based on remainder invariance. The method comprises a watermark embedding process and a watermark extraction and original image recovery process. A integer transformation provided by the invention removes additive terms and reduces embedding distortion; the integer transformation is composed of only a prediction process, and involves predicting each pixel in a block by using the mean value of the block, enabling each prediction error before a final prediction error in a sub-block to carry watermarking information and enabling a final pixel to be only predicted but carry no watermarking information so as to ensure the reversibility of the integer transformation; and by using the characteristic that the remainder obtained through the mean value of an image sub-block being divided by a given embedding parameter remains untransformed beforehand and afterwards, the integer transformation can help to recover original pixels and watermarking information without distortion. Therefore, by the provided method, improvements to a great extent are made in terms of both embedding capacity and recovery image quality.

The embodiment of the invention discloses a method and device for embedding and extracting a reversible watermarking as well as a method and device for recovering an image and relates to the technical field of image information safety. The method for embedding the reversible watermarking provided by the embodiment of the invention comprises the following steps: acquiring congregation classification information and watermarking information of a macro-block in an original image, wherein the congregation classification information comprises a first congregation, a second congregation and a third congregation; establishing a position chart related to an embedded quantity for each macro-block in the first and second congregations; and embedding the information in the position chart related to the embedded quantity and the watermarking information into the corresponding macro-blocks, according to the arrayed sequence of the macro-blocks and the congregation classification of the macro-blocks. By using the method provided by the embodiment of the invention, the embedding volume is increased and the embedding distortion is reduced.

The invention discloses a high-capacity data protection method based on a GAN augmented image foreground object. By applying various GANs to information hiding, the high-capacity data protection method obtains an embedded distortion probability graph, calculates an unsuitable steganography area according to the embedded distortion probability graph, generates a foreground object in the unsuitablesteganography area through a fixed area object generation and information embedding module, and then hides the secret information in the generated graph. The high-capacity data protection method mainly comprises the following steps: (1) inputting an original image into a steganography probability graph generator; (2) calculating the steganography probability graph; (3) calculating the unsuitable steganography area; (4) adding a texture object into the original image; and (5) carrying out an information hiding algorithm to embed secret information. According to the high-capacity data protectionmethod, the unsuitable hidden area is calculated for the image in advance, so that the directional hiding capability of the unsuitable hidden area of the original image in information hiding is improved; and provided is a high-capacity data protection method which increases hiding capacity and has high security.

The invention provides a self-adaptive reversible watermark method and system. The method comprises the following steps of: dividing a carrier image into a plurality of adjacent pixel pairs which arenot coincident; calculating corresponding difference values by utilizing a gradient prediction method and generating a two-dimensional difference value histogram; selecting an optimum path in the two-dimensional difference value histogram by adoption of a dynamic planning algorithm, and establishing a first corresponding relationship between pixels corresponding to a difference value pair on the optimum path and bit information carried by a to-be-embedded watermark; if the difference value corresponding to the pixel pair is not on the optimum path, modifying the pixel pair according to a preset first rule; if the difference value corresponding to the pixel is on the optimum path and a value of the bit information corresponding to the pixel pair is 1, modifying the pixel pair according to the preset first rule and the first corresponding relationship; and if the value of the bit information corresponding to the pixel pair is 0, not modifying the pixel pair. The method and system are high in data embedding capacity, low in embedding distortion and high in hidden data safety.

The invention discloses a reversible watermark implementation method of an audio signal. The method comprises steps that a value of a left channel signal point is predicted through utilizing a first prediction model to obtain a residual error; the residual error is utilized to distinguish different smooth regions of a right channel signal, and an optimal right channel signal slip region is selected through utilizing the optimization algorithm; a value of each point in the optimal right channel signal slip region is predicted through utilizing a second prediction module, a residual error is obtained, and the spread method is utilized for embedding and extraction recovery of the watermark information. The method is advantaged in that the audio embedding capacity is improved while audio embedding distortion is greatly reduced, an original audio can be restored losslessly after watermark extraction, and the method can be applied to authenticity and nondestructive authentication of audio signals.

The invention discloses a high-capacity reversible watermark embedding and extracting method, which mainly includes the following steps: calculating prediction errors of pixel predicted values of all pixels in an image; constructing a statistic column diagram according to the prediction errors, dividing the pixels in the image into an embeddable pixel set embedded with watermark data, and a movable pixel set capable of moving horizontally; and embedding the watermark data into the pixels with the prediction errors lower than a set threshold value. During embedding, one bit or multiple bits of watermark information is embedded into a single pixel in a self-adaptive manner according to the texture complexity of the image, so that the single embedding rate can achieve more than 2BPP (bits per pixel), and the embedding capability is efficiently improved. In addition, even multiple bits of watermark information are embedded into the single pixel, the used prediction error are still the original prediction errors, therefore, the embedding distortion is efficiently lowered, namely, the higher image quality is ensured on the premise that the embedding capability is efficiently improved.

The invention provides an audio stream information embedding method and device and an audio stream information decoding method and device. The target gain value is determined according to the voice frame, and then a second target index or a third target index is determined according to the target gain value and a second gain quantization table and bits to be embedded so as to realize embedding ofthe information. The technical scheme has relatively high steganography capacity and can resist general steganography analysis and detection, and the embedding distortion of the synthetic voice is lowand the effect of objective and subjective evaluation of the voice quality is good.

The embodiment of the invention discloses a method and device for embedding and extracting a reversible watermarking as well as a method and device for recovering an image and relates to the technical field of image information safety. The method for embedding the reversible watermarking provided by the embodiment of the invention comprises the following steps: acquiring congregation classification information and watermarking information of a macro-block in an original image, wherein the congregation classification information comprises a first congregation, a second congregation and a third congregation; establishing a position chart related to an embedded quantity for each macro-block in the first and second congregations; and embedding the information in the position chart related to the embedded quantity and the watermarking information into the corresponding macro-blocks, according to the arrayed sequence of the macro-blocks and the congregation classification of the macro-blocks. By using the method provided by the embodiment of the invention, the embedding volume is increased and the embedding distortion is reduced.

The invention discloses a high-capacity reversible watermarking method based on an adaptive prediction model; it includes a watermark embedding process, watermark extraction and original image restoration process; the watermark embedding process includes a prediction model design process and an adaptive embedding strategy; The process of watermark extraction and original image recovery is the inverse process of the watermark embedding process; the present invention obtains a prediction model with high prediction performance by making full use of the characteristics of high correlation between adjacent pixels, thereby effectively reducing the The high embedding distortion generated when watermark embedding is modified by the prediction error; in addition, by evaluating the correlation degree of the four surrounding pixels of each pixel in the set to be embedded, about three quarters of all pixels can carry 1‑ A 2-bit watermark, therefore, achieves an increase in capacity.

The invention discloses a reversible watermarking algorithm based on PVO (Pixel Value Ordering) and self-adaptive block segmentation and belongs to the field of multimedia information security. According to the algorithm, an image block is roughly segmented into two categories according to the complexity of local texture characteristics: a smooth block and a texture block; the smooth block is then subdivided into two sub-categories according to the correlation degree of a pixel in blocks: blocks with low smoothness and blocks with high smoothness. The blocks with low smoothness are ordered according to the sequence of pixel values from low to high to obtain psigma (1), psigma(2),to psigma (n); psigma(n-1) and psigma (n) are predicted by using psigma (n-2) or psigma(2) and psigma (1) are predicted by using psigma (3); one block with low smoothness can carry watermarking information of four bits at most. The blocks with high smoothness are segmented into sub-blocks which only contain three pixels respectively, that is (p1, p2 and p3), p1, p2 and p3 are ordered to obtain psigma (1), psigma (2) and psigma (3). According to the reversible watermarking algorithm based on PVO and self-adaptive block segmentation, the purpose of modifying psigma (1) and psigma (2) is achieved by only modifying psigma (3), the embedding distortion is greatly reduced.

The invention discloses a color image reversible digital watermarking method based on a three-dimensional prediction error histogram. The method comprises steps: a watermark is embedded and extracted; through changing a prediction error group mapping relationship in the three-dimensional prediction error histogram, mapping with large embedding distortion is abandoned, mapping is divided into mapping whose embedding distortion is no more than 2 and mapping whose embedding distortion is no more than 1, and a reversible watermark is embedded in a new mapping relationship rebuilding method. Distortion of the image can be avoided to a certain degree, and the PSNR of the image is improved. The method can be used for hiding of secret information; and through applying a double-layer embedding scheme based on a diamond prediction model and building the prediction error group mapping relationship different from the previous one, less image distortion under the same embedding capacity can be realized.

The invention discloses a reversible watermark implementation method of an audio signal. The method comprises steps that a value of a left channel signal point is predicted through utilizing a first prediction model to obtain a residual error; the residual error is utilized to distinguish different smooth regions of a right channel signal, and an optimal right channel signal slip region is selected through utilizing the optimization algorithm; a value of each point in the optimal right channel signal slip region is predicted through utilizing a second prediction module, a residual error is obtained, and the spread method is utilized for embedding and extraction recovery of the watermark information. The method is advantaged in that the audio embedding capacity is improved while audio embedding distortion is greatly reduced, an original audio can be restored losslessly after watermark extraction, and the method can be applied to authenticity and nondestructive authentication of audio signals.