Abstract: An intermediate bitstream generated by a first-stage transcoding system from an initial transmission package is received. The intermediate bitstream comprises base layer (BL) and enhancement layer (EL) signals. The combination of the BL and EL signals of the intermediate bitstream represents compressed wide dynamic range images. The BL signal of the intermediate bitstream alone represents compressed standard dynamic range images. A targeted transmission package is generated based on the intermediate bitstream. The targeted transmission package comprises BL and EL signals. The BL signal of the targeted transmission package may be directly transcoded from the BL signal of the intermediate bitstream alone.

Abstract: Video data with both ultra-high definition (UHD) resolution and high or enhanced dynamic range (EDR) data are coded in a backward-compatible layered stream which allows legacy decoders to extract an HD standard dynamic range (SDR) signal. In response to a base layer HD SDR signal, a predicted signal is generated using separate luma and chroma prediction models. In the luma predictor, luma pixel values of the predicted signal are computed based only on luma pixel values of the base layer, while in the chroma predictor, chroma pixel values of the predicted signal are computed based on both the luma and the chroma pixel values of the base layer. A residual signal is computed based on the input UHD EDR signal and the predicted signal. The base layer and the residual signal are coded separately to form a coded bitstream. A compatible dual-layer decoder is also presented.

Abstract: An encoder receives a target image in a standard dynamic range and a guide image in a high dynamic range, wherein both the target image and the guide image represent the same scene. A color transient improvement (CTI) filter is selected to predict a chroma component of a decoded version of the target image based on both the luma and chroma components of the target image and the guide image. The filtering coefficients for the CTI filter are computed by minimizing an error measurement (e.g., MSE) between pixel values of the decoded image and the guide image. The computed set of filtering coefficients is signaled to a receiver (e.g., as metadata). A decoder receives the coded image and the metadata, and applies the same CTI filter to the decoded image to generate an output image.

Abstract: A sequence of visual dynamic range (VDR) images is encoded using a standard dynamic range (SDR) base layer and one or more enhancement layers. A predicted VDR image is generated from an SDR input by using a weighted, multi-band, cross-color channel prediction model. Exponential weights with an adaptable decay parameter for each band are also presented.

Abstract: An encoder receives a first image of a first spatial resolution and a second image of a second spatial resolution, wherein both the first image and the second image represent the same scene and the second spatial resolution is higher than the first spatial resolution. A filter is selected to up-sample the first image to a third image with a spatial resolution same as the second spatial resolution. The filtering coefficients for the up-sampling filter are computed by minimizing an error measurement (e.g., MSE) between pixel values of the second image and the third image. The computed set of filtering coefficients is signaled to a receiver (e.g., as metadata). A decoder receives the first image (or its approximation) and the metadata, and may up-sample the first image using the same filter and optimally selected filtering coefficients as those derived by the encoder.

Abstract: In layered VDR coding, inter-layer residuals are quantized by a non-linear quantizer before being coded by a subsequent encoder. Several non-linear quantizers are presented. Such non-linear quantizers may be based on sigmoid-like transfer functions, controlled by one or more free parameters that control their mid-range slope. These functions may also depend on an offset, an output range parameter, and the maximum absolute value of the input data. The quantizer parameters can time-vary and are signaled to a layered decoder. Example non-linear quantizers described herein may be based on the mu-law function, a sigmoid function, and/or a Laplacian distribution.

Abstract: 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.

Abstract: Error control in multi-stream visual dynamic range (VDR) codecs is described, including for a case of a layer-decomposed (non-backward compatible) video codecs. Error control can be provided by concealing lost and/or corrupted data in data frames of a decoded VDR bitstream prior to rendering a corresponding VDR image. Various algorithms and methods for concealing lost and/or corrupted data are provided.

Abstract: A sequence of visual dynamic range (VDR) images is encoded using a standard dynamic range (SDR) base layer and one or more enhancement layers. A predicted VDR image is generated from an SDR input by using a weighted, multi-band, cross-color channel prediction model. Exponential weights with an adaptable decay parameter for each band are also presented.

Abstract: In an embodiment, a control map of false contour filtering is generated for a predicted image. The predicted image is predicted from a low dynamic range image mapped from the wide dynamic range image. Based at least in part on the control map of false contour filtering and the predicted image, one or more filter parameters for a sparse finite-impulse-response (FIR) filter are determined. The sparse FIR filter is applied to filter pixel values in a portion of the predicted image based at least in part on the control map of false contour filtering. The control map of false contour filtering is encoded into a part of a multi-layer video signal that includes the low dynamic range image.

Abstract: A sequence of visual dynamic range (VDR) images may be encoded using a standard dynamic range (SDR) base layer and one or more enhancement layers. A prediction image is generated by using piecewise cross-color channel prediction (PCCC), wherein a color channel in the SDR input may be segmented into two or more color channel segments and each segment is assigned its own cross-color channel predictor to derive a predicted output VDR image. PCCC prediction models may include first order, second order, or higher order parameters. Using a minimum mean-square error criterion, a closed form solution is presented for the prediction parameters for a second-order PCCC model. Algorithms for segmenting the color channels into multiple color channel segments are also presented.

Abstract: A sequence of visual dynamic range (VDR) images may be encoded using a standard dynamic range (SDR) base layer and one or more enhancement layers. A prediction image is generated by using piecewise cross-color channel prediction (PCCC), wherein a color channel in the SDR input may be segmented into two or more color channel segments and each segment is assigned its own cross-color channel predictor to derive a predicted output VDR image. PCCC prediction models may include first order, second order, or higher order parameters. Using a minimum mean-square error criterion, a closed form solution is presented for the prediction parameters for a second-order PCCC model. Algorithms for segmenting the color channels into multiple color channel segments are also presented.

Abstract: This disclosure describes tools capable of generating messages for use in deblocking filtering a video stream, the messages based on prediction parameters extracted from the video stream.

Abstract: A visual dynamic range (VDR) coding system creates a sequence of VDR prediction images using corresponding standard dynamic range (SDR) images and a prediction function. For each prediction image, an encoder identifies one or more areas within the prediction image suitable for post-prediction filtering. For each identified post-prediction area, a post-prediction filtering mode is selected among one or more post-prediction filtering modes. The selected post-prediction filtering mode is applied to output a filtered prediction image. Information related to the post-prediction filtering areas and the selected corresponding post-prediction filtering modes may be communicated to a receiver (e.g., as metadata) for guided post-prediction filtering. Example post-prediction filtering modes that use low-pass averaging filtering or adaptive linear interpolation are also described.

Abstract: Coding syntaxes in compliance with same or different VDR specifications may be signaled by upstream coding devices such as VDR encoders to downstream coding devices such as VDR decoders in a common vehicle in the form of RPU data units. VDR coding operations and operational parameters may be specified as sequence level, frame level, or partition level syntax elements in a coding syntax. Syntax elements in a coding syntax may be coded directly in one or more current RPU data units under a current RPU ID, predicted from other partitions/segments/ranges previously sent with the same current RPU ID, or predicted from other frame level or sequence level syntax elements previously sent with a previous RPU ID. A downstream device may perform decoding operations on multi-layered input image data based on received coding syntaxes to construct VDR images.

Abstract: An encoder receives a sequence of images in extended or visual dynamic range (VDR). For each image, a dynamic range compression function and associated parameters are selected to convert the input image into a second image with a lower dynamic range. Using the input image and the second image, a residual image is computed. The input VDR image sequence is coded using a layered codec that uses the second image as a base layer and a residual image that is derived from the input and second images as one or more residual layers. Using the residual image, a false contour detection method (FCD) estimates the number of potential perceptually visible false contours in the decoded VDR image and iteratively adjusts the dynamic range compression parameters to prevent or reduce the number of false contours. Examples that use a uniform dynamic range compression function are also described.

Abstract: Inter-color image prediction is based on multi-channel multiple regression (MMR) models. Image prediction is applied to the efficient coding of images and video signals of high dynamic range. MMR models may include first order parameters, second order parameters, and crosspixel parameters. MMR models using extension parameters incorporating neighbor pixel relations are also presented. Using minimum means-square error criteria, closed form solutions for the prediction parameters are presented for a variety of MMR models.

Abstract: An encoder receives a sequence of images in extended or visual dynamic range (VDR). For each image, a dynamic range compression function and associated parameters are selected to convert the input image into a second image with a lower dynamic range. Using the input image and the second image, a residual image is computed. The input VDR image sequence is coded using a layered codec that uses the second image as a base layer and a residual image that is derived from the input and second images as one or more residual layers. Using the residual image, a false contour detection method (FCD) estimates the number of potential perceptually visible false contours in the decoded VDR image and iteratively adjusts the dynamic range compression parameters to prevent or reduce the number of false contours. Examples that use a uniform dynamic range compression function are also described.

Abstract: In an embodiment, a rate-adaptation unit may be configured to receive local as well as end-to-end feedback information associated with data transmission (such as data delay, packet loss, transmit power headroom, channel condition; sector loading, the amount of buffered data, etc.) from a wireless access module in communication with wireless/wired networks, and adapt the real-time information encoding in accordance with such feedback information.

Abstract: Inter-color image prediction is based on color grading modeling. Prediction is applied to the efficient coding of images and video signals of high dynamic range. Prediction models may include a color transformation matrix that models hue and saturation color changes and a non-linear function modeling color correction changes. Under the assumption that the color grading process uses a slope, offset, and power (SOP) operations, an example non linear prediction model is presented.