Abstract: An encoding apparatus is described for signaling an extension directional intra-prediction mode within a set of directional intra-prediction modes, the set of directional intra-prediction modes comprising predetermined directional intra-prediction modes and the extension directional intra-prediction mode. The encoding apparatus comprises a mode mapping unit selecting a predetermined directional intra-prediction mode, the selected predetermined directional intra-prediction mode being associated with an intra mode index, and mapping the extension directional intra-prediction mode onto the selected predetermined directional intra-prediction mode. A signaling unit generates a signaling indicator comprising at least one of the intra mode index and a flag value. An intra-prediction unit intra-predicts pixel values of pixels of a rectangular video coding block on the basis of the extension directional intra-prediction mode for providing a predicted rectangular video coding block.

Abstract: Devices and methods for video coding are described. One method comprises receiving a bitstream, wherein the bitstream comprises prediction related information, and wherein the prediction related information includes at least one of: numbers and positions of available primary reference samples, an intra prediction mode index, or a size of the current coding block; determining whether a bidirectional intra prediction (BIP) flag is signaled in the bitstream based on the prediction related information; and reconstructing the picture.

Abstract: The present disclosure provides embodiments for coding and decoding signs of transform coefficients which is applicable, for instance, in image and/or video coding and decoding. In particular, a plurality of the signs are predicted and only a prediction error signal is embedded in the bitstream. The prediction error signal may have a distribution which can be efficiently coded with CABAC or another variable length (entropy) coding. Moreover, if adaptive multi-core transform is used, the context for the entropy code to code a transform coefficient sign is selected according to the transformation which was used to obtain the transform coefficient.

Abstract: Methods, systems, devices, and apparatus for image processing are provided. In one aspect, a method includes: intra-predicting a block of an image based on reference samples of the image, the reference samples being arranged in one or more reference sample sets each including a coherent set of reference samples and including one or more reference samples adjoining the block; segmenting each of the one or more reference sample sets into a sequence of three or more subsets including a first subset, a last subset, and one or more intermediary subsets located therebetween; determining a weight value for each subset, weight values of the one or more intermediary subsets being lower than weight values of the first subset and the last subset; fitting a plane to the reference samples of the image using the determined weight values; and generating an intra-predicted block based on the plane.

Abstract: A current video coding block of a frame of a video signal is intra predicted. The current video coding block comprises a plurality of pixels and each pixel is associated with a pixel value. On the basis of a plurality of primary reference pixel values a plurality of secondary reference pixel values are generated. The plurality of primary reference pixel values are associated with a plurality of primary reference pixels located in neighboring video coding blocks of the current video coding block. Each of the secondary reference pixel values is generated on the basis of two or more of the primary reference pixel values. The pixel values of the pixels of the current video coding block are intra predicted on the basis of the plurality of primary reference pixel values and the plurality of secondary reference pixel values.

Abstract: A decoding device and a decoding method for decoding a target information from a bitstream of video data are provided, wherein the bitstream comprises a prediction parameter encoded in the bitstream. The decoding device is configured to calculate a randomized host signal based on the prediction parameter and a pseudo-random signal, and to apply a check function to the randomized host signal and thereby obtain the target information. An encoding device and an encoding method, and computer-readable storage media for encoding and for decoding are also disclosed.

Abstract: Devices and methods of intra prediction of a block of a picture are provided. In various embodiments, information indicating an Intra Sub-Partitions (ISP) split type can be obtained. A value of a filter flag can be set based on the ISP split type. For instance, the value of the filter flag can be set to 0 when the ISP split type does not indicate not to split a current block. A set of coefficients of an interpolation filter can then be selected according to the value of the filter flag. For instance, fG coefficients or fC coefficients can be selected based on the value of the filter flag. Still in those embodiment, the selected set of coefficients can be applied to reference samples. In some embodiments, the method removes mode dependency during selection of interpolation filter type. This could increase encoding or decoding efficiency.

Abstract: The present disclosure relates to provision of a mechanism for deciding whether and/or for which set of transformation coefficients resulting from a transformation of some source signal a sign of a current transformation coefficient may be embedded into a value of a function of that set of transformation coefficients. In particular, the decision is based on a condition including evaluating a second function of the transform coefficient values in the set of transform coefficients and a number of those transform coefficients in the set which are larger than a coefficient value threshold. The corresponding decoder for is also provided.

Abstract: The present invention relates to an improved apparatus and method for harmonizing both Sign Bit Hiding (SBH) and Residual Sign Prediction (RSP) techniques in video coding. In order to improve coding efficiency, a list of transform coefficients, to which RSP is to be applied is prepared in advance of selecting a coefficient to which SBH is applied. Thereby, the RSP list can be populated in such a manner that the highest coding efficiency may be expected. Subsequently, one or more coefficients for applying SBH are selected so as not to be included in the list.

Abstract: The present disclosure provides embodiments for coding and decoding signs of transformation coefficients which is applicable, for instance, in image and/or video coding and decoding. In particular, a plurality of the signs are predicted and only a prediction error signal is embedded in the bitstream. The prediction error signal may have a distribution which can be efficiently coded with CABAC or another variable length (entropy) coding. In order to perform the prediction of the signs efficiently, the signs of a plurality of coefficients of a transformed image block are predicted based on a cost function including transformed difference between adjacent pixels neighboring the transformed image block and prediction of the adjacent pixels calculated based on a prediction signal of the image block.

Abstract: An intra-prediction apparatus extends a set of predetermined directional intra-prediction modes of a rectangular video coding block. The intra-prediction apparatus determines an aspect ratio of the rectangular video coding block, and determines a complementary angle range based on the aspect ratio. The apparatus then selects a complementary direction within the complementary directional range, and adds an extension directional intra-prediction mode associated with the complementary direction to the set of predetermined directional intra-prediction modes. Based on the extension directional intra-prediction mode, the apparatus intra-predicts pixel values of pixels of the rectangular video coding block.

Abstract: A decoding device and a decoding method for decoding a target information from a bitstream of video data are provided, wherein the bitstream comprises a prediction parameter encoded in the bitstream. The decoding device is configured to calculate a randomized host signal based on the prediction parameter and a pseudo-random signal, and to apply a check function to the randomized host signal and thereby obtain the target information. An encoding device and an encoding method, and computer-readable storage media for encoding and for decoding are also disclosed.

Abstract: The disclosure proposes a decoder for decoding coefficients of blocks of a video sequence from a bitstream. The decoder comprises a decoding module configured to decode one or more coefficient vectors of each block from the bitstream, a check module configured to reconstruct, for at least one block, hidden information from one or more coefficients of that block, the hidden information constituting or forming part of scan order information associated with that block, a scan order selector configured to select a scan order for each block from a set of scan orders, preferably from a set of pre-defined and generated scan orders, on the basis of the scan order information associated with that block, and a deserializer configured to inverse scan, for each block, the one or more coefficient vectors of that block according to the scan order selected for that block so as to obtain a coefficient matrix.

Abstract: A method and apparatus for adaptively processing video samples in a video signal frame, the video samples being arranged in a Largest Coding Unit. The method comprises extracting a plurality of video samples from the Largest Coding Unit, calculating a correction offset for a first video sample of the extracted plurality of video samples upon the basis of a first value of the first video sample and a second value of a second video sample of the extracted plurality of video samples, and weighting the first video sample with the correction offset.

Abstract: An apparatus and a method for image coding with asymmetric partitioning are disclosed. Instead of a conventional approach of using partitioning mechanisms such as QTBT and Multi-Type Tree (MTT), an asymmetric partitioning mechanism that can provide a good performance/complexity tradeoff is introduced. This allows constraining parameters of the asymmetric partitioning mechanism to exclude modes that appear not frequently, thereby allowing keeping encoder-side complexity low and avoiding signaling overhead.

Abstract: A picture encoding apparatus configured to hierarchically partition a block of picture data into sub-blocks; determine that a sub-block being coded belongs to an unequally-sized partitioned block; prepare a list of neighboring blocks for the sub-block of the unequally-sized partitioned block based on a size of the sub-block of the unequally-sized partitioned block and a partitioning type of at least one neighboring block of the unequally-sized partitioned block; and derive a context model that is used to encode split information of the sub-block of the unequally-sized partitioned block into a bit stream based on the prepared list of neighboring blocks.

Abstract: A method and apparatus for adaptively processing video samples in a video signal frame, the video samples being arranged in a Largest Coding Unit. The method comprises extracting a plurality of video samples from the Largest Coding Unit, calculating a correction offset for a first video sample of the extracted plurality of video samples upon the basis of a first value of the first video sample and a second value of a second video sample of the extracted plurality of video samples, and weighting the first video sample with the correction offset.

Abstract: Encoded video data is decoded to provide a residual video coding block. An intra-prediction mode identifier is extracted from the encoded video data. A predicted video coding block is generated on the basis of a selected intra-prediction mode. A plane-based intra-prediction mode and a further intra-prediction mode are pre-selected if the extracted intra-prediction mode identifier is equal to a first predefined intra-prediction mode identifier. Either the plane-based intra-prediction mode or the further intra-prediction mode are selected, based on (a) an additional flag extracted from the encoded video data or (b) a deviation measure. The deviation measure quantifies deviations of a plurality of reference samples from neighbouring video coding blocks from a plurality of fitting samples defined by a fitting plane based on the plurality of reference samples. A video coding block is restored on the basis of the residual video coding block and the predicted video coding block.

Abstract: A video coding block is intra-predicted on the basis of a plurality of primary reference samples from a first set of neighboring video coding blocks. A fitting plane is determined on the basis of the plurality of primary reference samples and defines a plurality of fitting samples. For a selected directional intra prediction mode, a plurality of secondary reference samples are generated on the basis of the plurality of primary reference samples and the plurality of fitting samples. The secondary reference samples are located in a second set of neighboring video coding blocks. The sample values of the current video coding block are predicted on the basis of the plurality of primary reference sample values and the plurality of secondary reference sample values.

Abstract: A video coding block is intra-predicted on the basis of reference samples from a set of neighboring video coding blocks. A fitting plane is determined on the basis of the reference samples. The fitting plane defines a plurality of fitting samples. For a selected directional intra prediction mode, the sample values of the video coding block are predicted on the basis of the reference sample values and the fitting sample values.