Abstract: In a method to improve the coding efficiency of high-dynamic range images coded in a perceptually quantized IPT color space (IPT-PQ), the values of the chroma components (P/T) of an input signal in IPT-PQ color space are divided by a factor of two before being encoded with standard-based encoders, such as AVC or HEVC; thus better matching the covariance characteristics of YCbCr signals. In addition, the order of the P and T chroma components may be swapped and the sign of the T chroma component may be inverted. Color transformation matrices for efficient forward and backward reshaping in the IPT-PQ color space are provided.

Abstract: Methods to improve the quality of coding high-dynamic range (HDR) signals are presented. Instead of using a single chroma quantization table for all color formats, a video encoder may adaptively use separate tables for each one, and transmit the table's ID to a decoder. Examples for chroma quantization tables for video content encoded in the YCbCr (PQ) and ICtCp (PQ) color formats under a variety of color gamut containers are provided.

Abstract: In a method to improve backwards compatibility when decoding high-dynamic range images coded in a wide color gamut (WCG) space which may not be compatible with legacy color spaces, hue and/or saturation values of images in an image database are computed for both a legacy color space (say, YCbCr-gamma) and a preferred WCG color space (say, IPT-PQ). Based on a cost function, a reshaped color space is computed so that the distance between the hue values in the legacy color space and rotated hue values in the preferred color space is minimized HDR images are coded in the reshaped color space. Legacy devices can still decode standard dynamic range images assuming they are coded in the legacy color space, while updated devices can use color reshaping information to decode HDR images in the preferred color space at full dynamic range.

Abstract: Given existing color remapping information (CRI) messaging variables, methods are described to communicate color volume information for a targeted display to a downstream receiver. Bits 7:0 of the 32-bit colour_remap_id are used to extract a first value. If the first value is not a reserved value, then the first value is used as an index to a look-up table to generate a first luminance value for a targeted display, otherwise a second value is generated based on bits 31:9 in the colour_remap_id messaging variable and the first luminance value for a targeted display is generated based on the second value. The methods may be applied to communicate via CRI messaging a minimum luminance value, a maximum luminance value, and color primaries information of the targeted display.

Abstract: Methods, processes, and systems are presented for adaptive loop filtering in coding and decoding high dynamic range (HDR) video. Given an input image block, its luminance information may be used to adapt one or more parameters of adaptive loop filtering and compute gradient and directionality information, activity information, a classification index, and adaptive-loop-filtering coefficients.

Abstract: Methods for the chroma reshaping of high-dynamic range (HDR) signals are presented. For each input pixel, a first scaler is generated based on the pixel luminance and a luma-based chroma reshaping (LCR) function. A second scaler is generated based on a saturation-based chroma reshaping (SCR) function and the saturation value of the pixel. A cascaded scaler is generated by multiplying the first scaler with the second scaler. Reshaped chroma values are generated by multiplying the input chroma values with the cascaded scaler. The characteristics of preferred LCR and SCR functions are discussed. Inverse decoding methods based on chroma-reshaping metadata that define the LCR and SCR functions are also described.

Abstract: Methods to improve the quality of coding high-dynamic range (HDR) signals in the ICtCp color space are presented. Techniques are described to a) generate optimum chroma Offset and scaling parameters, b) compute chroma mode decisions by optimizing mode selection distortion metrics based on chroma saturation and hue angle values, and c) preserving iso-luminance by maintaining in-gamut values during chroma down-sampling and chroma up-sampling operations.

Abstract: In an embodiment, an apparatus and method of creating a skimming preview of a video includes electronically receiving a plurality of video shots, analyzing each frame in a video shot from the plurality of video shots, where analyzing includes determining a saliency of each frame of the video shot. The method also includes determining a key frame of the video shot based on the saliency of each frame the video shot, extracting visual features from the key frame, performing shot clustering of the plurality of video shots to determine concept patterns based on the visual features, and generating a reconstruction reference tree based on the shot clustering. The reconstruction reference tree includes video shots categorized according to each concept pattern.

Abstract: The precision of up-sampling operations in a layered coding system is preserved when operating on video data with high bit-depth. In response to bit-depth requirements of the video coding or decoding system, scaling and rounding parameters are determined for a separable up-scaling filter. Input data are first filtered across a first spatial direction using a first rounding parameter to generate first up-sampled data. First intermediate data are generated by scaling the first up-sampled data using a first shift parameter. The intermediate data are then filtered across a second spatial direction using a second rounding parameter to generate second up-sampled data. Second intermediate data are generated by scaling the second up-sampled data using a second shift parameter. Final up-sampled data may be generated by clipping the second intermediate data.

Abstract: The disclosure relates to handling nuisance in teleconference system. An endpoint device (400) for use in a teleconference includes an acquiring unit (401), a judging unit (402), a controller (403) and a processing unit (404). The acquiring unit acquires a media stream for presentation in the teleconference, and receives information from another device. The information includes a first estimation on whether the media stream is a nuisance to the teleconference. As the nuisance to a teleconference, audio or video signals are perceived by users as actually not relevant to the conference session or causing unpleasant feeling or confusion. The judging unit decides whether the media stream is the nuisance at least based on the information. The controller controls the processing of the media stream to degrade or suppress the presentation of the media stream in case that the media stream is decided as the nuisance. The processing unit processes the media stream under the control of the controller.

Abstract: A processor for forward reshaping to a target bit depth receives an input image with an input bit depth. The input luminance range is divided into luminance bands and each band is assigned a visual importance index. The output codewords at the target bit depth are divided into codeword bins and each bin is assigned to one of the luminance bands. Each codeword bin is assigned the visual importance index of the luminance band it belongs. Each bin is allocated a number of reshaped codewords according to its visual importance index and a codeword mapping function, where bins with the highest importance index are allocated more codewords than the other bins. A signal reshaping function is generated based on the allocation of codewords, and the reshaping function is applied to the input image to generate an output image in the target bit depth.

Abstract: The precision of up-sampling operations in a layered coding system is preserved when operating on video data with high bit-depth. In response to bit-depth requirements of the video coding or decoding system, scaling and rounding parameters are determined for a separable up-scaling filter. Input data are first filtered across a first spatial direction using a first rounding parameter to generate first up-sampled data. First intermediate data are generated by scaling the first up-sampled data using a first shift parameter. The intermediate data are then filtered across a second spatial direction using a second rounding parameter to generate second up-sampled data. Second intermediate data are generated by scaling the second up-sampled data using a second shift parameter. Final up-sampled data may be generated by clipping the second intermediate data.

Abstract: In an embodiment, a method of creating a skimming preview of a video includes electronically receiving a plurality of video shots, analyzing each frame in a video shot from the plurality of video shots, where analyzing includes determining a saliency of each frame of the video shot. The method also includes determining a key frame of the video shot based on the saliency of each frame the video shot, extracting visual features from the key frame, performing shot clustering of the plurality of video shots to determine concept patterns based on the visual features, and generating a reconstruction reference tree based on the shot clustering. The reconstruction reference tree includes video shots categorized according to each concept pattern.

Abstract: A high dynamic range input video signal characterized by either a gamma-based or a perceptually-quantized (PQ) source electro-optical transfer function (EOTF) is to be compressed. Given a luminance range for an image-region in the input, for a gamma-coded input signal, a rate-control adaptation method in the encoder adjusts a region-based quantization parameter (QP) so that it increases in highlight regions and decreases in dark regions, otherwise, for a PQ-coded input, the region-based QP increases in the dark areas and decreases in the highlight areas.

Abstract: A high resolution 3D image may be encoded into a first multiplexed image frame and a second multiplexed image frame in a base layer (BL) video signal and an enhancement layer (EL) video signal. The first multiplexed image frame may comprise horizontal high resolution image data for both eyes, while the second multiplexed image frame may comprise vertical high resolution image data for both eyes. Encoded symmetric-resolution image data for the 3D image may be distributed to a wide variety of devices for 3D image processing and rendering. A recipient device may reconstruct reduced resolution 3D image from one of the first multiplexed image frame or the second multiplexed image frame. A recipient device may also reconstruct high resolution 3D image by combining high resolution image data from both of the first multiplexed image frame and the second multiplexed image frame.

Abstract: In a method to improve backwards compatibility when decoding high-dynamic range images coded in a wide color gamut (WCG) space which may not be compatible with legacy color spaces, hue and/or saturation values of images in an image database are computed for both a legacy color space (say, YCbCr-gamma) and a preferred WCG color space (say, IPT-PQ). Based on a cost function, a reshaped color space is computed so that the distance between the hue values in the legacy color space and rotated hue values in the preferred color space is minimized HDR images are coded in the reshaped color space. Legacy devices can still decode standard dynamic range images assuming they are coded in the legacy color space, while updated devices can use color reshaping information to decode HDR images in the preferred color space at full dynamic range.

Abstract: In a method to improve the coding efficiency of high-dynamic range (HDR) images, a decoder parses sequence processing set (SPS) data from an input coded bitstream to detect that an HDR extension syntax structure is present in the parsed SPS data. It extracts from the HDR extension syntax structure post-processing information that includes one or more of a color space enabled flag, a color enhancement enabled flag, an adaptive reshaping enabled flag, a dynamic range conversion flag, a color correction enabled flag, or an SDR viewable flag. It decodes the input bitstream to generate a preliminary output decoded signal, and generates a second output signal based on the preliminary output signal and the post-processing information.

Abstract: In a method to improve the coding efficiency of high-dynamic range images coded in a perceptually quantized IPT color space (IPT-PQ), the values of the chroma components (P/T) of an input signal in IPT-PQ color space are divided by a factor of two before being encoded with standard-based encoders, such as AVC or HEVC; thus better matching the covariance characteristics of YCbCr signals. In addition, the order of the P and T chroma components may be swapped and the sign of the T chroma component may be inverted. Color transformation matrices for efficient forward and backward reshaping in the IPT-PQ color space are provided.

Abstract: Methods to improve the quality of coding high-dynamic range (HDR) signals are presented. Instead of using a single chroma quantization table for all color formats, a video encoder may adaptively use separate tables for each one, and transmit the table's ID to a decoder. Examples for chroma quantization tables for video content encoded in the YCbCr (PQ) and ICtCp (PQ) color formats under a variety of color gamut containers are provided.

Abstract: Given existing color remapping information (CRI) messaging variables, methods are described to communicate color volume information for a targeted display to a downstream receiver. Bits 7:0 of the 32-bit colour_remap_id are used to extract a first value. If the first value is not a reserved value, then the first value is used as an index to a look-up table to generate a first luminance value for a targeted display, otherwise a second value is generated based on bits 31:9 in the colour_remap_id messaging variable and the first luminance value for a targeted display is generated based on the second value. The methods may be applied to communicate via CRI messaging a minimum luminance value, a maximum luminance value, and color primaries information of the targeted display.