Thomson Licensing

University System of Maryland

Interdigital Madison Patent Holdings

Contentarmor

Shan He

Jeffrey Adam Bloom

Dekun Zou

Tao Zhang

Min Wu

Wan-Yi Lin

Guan-Ming Su

Ashwin Deepak Swaminathan

Dong-Qing Zhang

Yinian Mao

Sitaram Bhagavathy

Avinash Laxmisha Varna

Hongmei Gou

Douglas W Oard

A confidentiality preserving system and method for performing a rank-ordered search and retrieval of contents of a data collection. The system includes at least one computer system including a search and retrieval algorithm using term frequency and/or similar features for rank-ordering selective contents of the data collection, and enabling secure retrieval of the selective contents based on the rank-order. The search and retrieval algorithm includes a baseline algorithm, a partially server oriented algorithm, and/or a fully server oriented algorithm. The partially and/or fully server oriented algorithms use homomorphic and/or order preserving encryption for enabling search capability from a user other than an owner of the contents of the data collection. The confidentiality preserving method includes using term frequency for rank-ordering selective contents of the data collection, and retrieving the selective contents based on the rank-order.

System and method for confidentiality-preserving rank-ordered search

A method and system for adjustable 3-dimensional content are described in which a viewer can adjust the depth range according to the viewer's own visual comfort level and/or viewing preference. The depth change is achieved by shifting the left and right images of stereoscopic content image pairs so that corresponding pixels in the shifted left and right images of a stereoscopic pair exhibit a new horizontal disparity sufficient to achieve the desired depth change. By shifting the left and right images in an image pair, content objects in the scene can appear closer to, or farther away from the viewer than those same objects in the un-shifted image pair. This technique achieves a viewer controlled customization of the sensation of depth in the stereoscopic 3-dimensional content.

Method and apparatus for customizing 3-dimensional effects of stereo content

Visual discomfort from depth jumps in 3D video content is reduced or avoided by detecting the occurrence of a depth jump and by changing the disparity of a group of received image frames including the frames at the depth jump in order to adjust the perceived depth in a smooth transition across the group of image frames from a first disparity value to a second disparity value. Depth jumps may be detected, for instance, when content is switched from one 3D shot to another 3D shot.

Method of presenting three-dimensional content with disparity adjustments

Method and apparatus for recovering a pruned version of a picture in a video sequence are disclosed. The apparatus includes a divider for dividing the pruned version of the picture into a plurality of non-overlapping blocks. The apparatus also includes a metadata decoder for decoding metadata for use in recovering the pruned version of the picture. The apparatus further includes a patch library creator for creating a patch library from a reconstructed version of the picture. The patch library includes a plurality of high resolution replacement patches for replacing the one or more pruned blocks during a recovery of the pruned version of the picture. The apparatus additionally includes a search and replacement device for performing a searching process using the metadata to find a corresponding patch for a respective one of the one or more pruned blocks from among the plurality of non-overlapping blocks and replace the respective one of the one or more pruned blocks with the corresponding patch. The signature is respectively created for each of the one or more pruned blocks, and the pruned version of the picture is recovered by comparing respective distance metrics from signatures for each of the plurality of high resolution patches to signatures for each of the one or more pruned blocks, sorting the respective distance metrics to obtain a rank list for each of the one or more pruned blocks, wherein a rank number in the rank list for a particular one of the one or more pruned blocks is used to retrieve a corresponding one of the plurality of high resolution patches in the patch library to be used to replace the particular one of the one or more pruned blocks. A patch dependency graph having a plurality of nodes and a plurality of edges is used to recover the pruned version of the picture. Each of the plurality of nodes represents a respective one of the plurality of overlapping blocks, and each of the plurality of edges represents a respective dependency of at least the respective one of the plurality of overlapping blocks.

Recovering a pruned version of a picture in a video sequence for example-based data pruning using intra-frame patch similarity

A method comprises accessing encoded video data; accessing a list of watermarks to the encoded video data; determining syntax elements for current blocks of video data and syntax elements of currents blocks with the watermarks; removing watermarks that cause visible artifacts based on differences in the syntax elements between the current blocks and current blocks with watermarks, thereby creating filtered list of acceptable watermarks. The method can further include determining coding variable ranges for the current block and current block with watermarks from the list; comparing the coding variable ranges for the current blocks and current blocks with watermarks from the list; and filtering out watermarks that yield coding variable ranges outside the coding variable ranges of the current blocks. Additionally, the method can include determining bit lengths of the current blocks and current blocks with watermarks from the list; comparing bit lengths of the current blocks and current blocks with watermarks from the list; and filtering out watermarks that yield bit lengths not equal to the bit lengths of the current blocks.

Changeable block list

A method for detecting and selecting watermarking in video coding is provided that comprises accessing a list of possible watermarks; generating propagation maps of modifications to the video that would be caused by applying the respective watermarks; generating a detection region responsive to each respective propagation map that includes blocks within the propagation map that collectively rank highest with respect to a selected detection criteria compared to each other region within the propagation map; selecting a threshold metric for evaluating detection regions; and removing watermarks from the list responsive to a comparison of their detection regions with the threshold metric.

Watermark detection using a propagation map

A method comprises receiving original encoded video stream as one input, accessing encoded data divided into slices which are further divided into blocks, receiving the list of possible changes or watermarks as another input, accessing at least one block, decoding each slice, setting down each slice, extracting from the list those changes that apply to the at least one block, and constructing propagation maps from inter-prediction or intra-prediction using changes for the at least one block. The method can further comprise decoding luminance data using the propagation maps, comparing the luminance data to a fidelity threshold, and applying possible changes or watermarks to those not exceeding the fidelity threshold.

Propagation map

A method and system of detecting colluders conducting a collusion attack including a minority-type collusion attack on a digital product includes the generation of codewords used as watermarks in the digital product. The inner code of the codewords is generated using permutations of rows in a Hadamard matrix and concatenating them together. A typical outer code of the codeword is the Reed Solomon code. An adaptive detector is able to accurately detect one of three or more colluders of a minority-type attack. Prior art schemes using an error correcting code-based watermarking mechanism with an inner code fail to detect colluders with a minority-type collusion attack which includes three colluders.

Method for protecting digital content against minority collusion attacks

A method comprises providing a change to apply to video; dividing video into blocks; creating propagation map which captures only specific changes to blocks that would be changed by the application of the change; evaluating the change based on a luminance criterion as being a perceptible change or an imperceptible change; for propagation maps of an imperceptible change, storing the propagation map to a list, wherein the propagation map is the principle data structure to be applied to the video. The propagation map can be created by using motion vector changes associated with the change.

Luminance evaluation

A method comprises accessing changes which can be watermarks in a list for coded data, the changes having an syntax element, an original value and an candidate alternative value; determining for a subset a group of compliant changes from the changes, the complaint changes being compliant with a coding protocol such as a CABAC encoding protocol; and selecting for the subset only compliant changes that result in the subset having only one candidate alternative value for each syntax elements and result in only compliant changes also meeting at least one performance criterion. The method can include determining fidelity, recoverability, or robustness of the watermarks and removing or preventing watermarks from being in the subset based on the fidelity, recoverability, or robustness, wherein fidelity, recoverability, and robustness are performance criteria. The method can include determining at least two performance values for the watermarks, determining some collective metric of the at least two performance values, and removing or preventing watermarks from being in the subset based on the same collective metric.

Selection of watermarks for the watermarking of compressed video

A method and apparatus are described including generating a unique code for each of a plurality of users using a plurality of symbols, generating a plurality of codes representing the plurality of symbols, substituting the plurality of codes into the unique code for each of the plurality of users, permuting the code resulting from the substitution to produce a codeword for each of the plurality of users and embedding the codeword into digital content. The second generating act further includes generating a string of first symbols followed by second symbols, wherein the first symbols are all ones and the second symbols are all negative ones, wherein a number of first symbols is equal to a number of the second symbols, and wherein if a length of the first symbols followed by the second symbols is less than a length of the code, then the first symbols followed by the second symbols are repeated until the code length is filled.

Method for constructing inner codes for anti-collusion forensic code for watermarking digital content

A method of providing CABAC compliant changes such as watermarks comprises accessing encoded data such as video which comprise at least two blocks; creating or accessing a list of changes to the encoded data that include a direct change to a block; determining motion character or motion vector differential of non-immediate block, non-immediate blocks being adjacent to an immediate block that are immediately adjacent to the block; determining change to the immediate block based on original motion character of the block and the non-immediate block and the motion character of the block that would result from the application of the change; storing the change to the list if the change does not cause a difference to the immediate block; and evaluating other potential changes if other potential changes are available, wherein the other potential changes are subjected to the same process steps as the direct change.

Context-based adaptive binary arithmetic coding (CABAC) video stream compliance

To identify participants in collusion directed to altering a digital fingerprint embedded in multimedia content, an ECC based fingerprinting technique establishes a code symbol for each of a plurality of segments of digital data forming the multimedia content. The code symbols are concatenated to form a fingerprint signal, which is subdivided into a plurality of subsegments for each segment in the digital data. The subsegments are permuted and embedded into the digital data. When a suspicious copy of the multimedia content is discovered, the permuted fingerprint signal is extracted from the content and inversely permuted to form a test fingerprint. The identity of one of the colluders is determined by correlation with characteristics of the codeword originally assigned to the user. The determination of identity may be enhanced by the addition of group data embedded as an additional fingerprint in the digital data. Joint consideration of coding and embedding provide benefits over previous fingerprinting techniques.

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Plainsboro, NJ, United States of America

Shan He