Abstract: Methods and apparatus of processing 360-degree virtual reality (VR360) pictures are disclosed. According to one method, if a leaf coding unit contains one or more face edges, the leaf processing unit is split into sub-processing units along the face edges without the need to signal the partition. In another method, if the quadtree (QT) of binary tree (BT) partition depth for a processing unit has not reached the maximum QT or BT depth, the processing unit is split. If the processing unit contains a horizontal face edge, QT or horizontal BT partition is applied. If the processing unit contains a vertical face edge, QT or vertical BT partition is applied.

Abstract: Methods and apparatus of processing 360-degree virtual reality images are disclosed. According to one method, the method receives coded data for an extended 2D (two-dimensional) frame including an encoded 2D frame with one or more encoded guard bands, wherein the encoded 2D frame is projected from a 3D (three-dimensional) sphere using a target projection, wherein said one or more encoded guard bands are based on a blending of one or more guard bands with an overlapped region when the overlapped region exists. The method then decodes the coded data into a decoded extended 2D frame including a decoded 2D frame with one or more decoded guard bands, and derives a reconstructed 2D frame from the decoded extended 2D frame.

Abstract: A luma-based chroma intra-prediction method includes: applying, by a filter circuit with a first weighting table, weighting to reconstructed luma samples to generate a first down-sampled luma sample, wherein the reconstructed luma samples are external to a luma block; computing parameters of a linear model, wherein a pair of the first down-sampled luma sample and a reconstructed chroma sample that is external to a chroma block is involved in computing the parameters of the linear model; and determining a predicted value of a chroma sample included in the chroma block according to the linear model and a second down-sampled luma sample that is derived from the luma block.

Abstract: Methods and apparatus of processing 360-degree virtual reality (VR360) pictures are disclosed. According to one method, if a leaf coding unit contains one or more face edges, the leaf processing unit is split into sub-processing units along the face edges without the need to signal the partition. In another method, if the quadtree (QT) of binary tree (BT) partition depth for a processing unit has not reached the maximum QT or BT depth, the processing unit is split. If the processing unit contains a horizontal face edge, QT or horizontal BT partition is applied. If the processing unit contains a vertical face edge, QT or vertical BT partition is applied.

Abstract: A video processing method includes: receiving a bitstream, wherein a part of the bitstream transmits encoded information of a projection-based frame that has a 360-degree content represented by projection faces packed in a 360-degree Virtual Reality (360 VR) projection layout, and the projection-based frame has at least one boundary; and decoding, by a video decoder, the part of the bitstream, including: generating a reconstructed frame, parsing a flag from the bitstream, and applying an in-loop filtering operation to the reconstructed frame. The flag indicates that the in-loop filtering operation is blocked from being applied to each of said at least one boundary in the reconstructed frame. In response to the flag, the in-loop filtering operation is blocked from being applied to each of the at least one boundary in the reconstructed frame.

Abstract: Methods and apparatus of processing 360-degree virtual reality (VR360) pictures are disclosed. According to one method, if a leaf coding unit contains one or more face edges, the leaf processing unit is split into sub-processing units along the face edges without the need to signal the partition. In another method, if the quadtree (QT) of binary tree (BT) partition depth for a processing unit has not reached the maximum QT or BT depth, the processing unit is split. If the processing unit contains a horizontal face edge, QT or horizontal BT partition is applied. If the processing unit contains a vertical face edge, QT or vertical BT partition is applied.

Abstract: A video processing method includes: receiving a part of a bitstream; decoding the part of the bitstream to generate a reconstructed projection-based frame with at least one projection face and at least one padding region packed in a projection layout of a 360-degree Virtual Reality (360 VR) projection; obtaining chroma sampling position information that is signaled via the bitstream; and performing a blending process for generating a blended chroma sample value at a target chroma sample position by blending a first chroma sample value obtained for a first chroma sample position in the at least one projection face and a second chroma sample value obtained for a second chroma sample position in the at least one padding region. At least one of the target chroma sample position, the first chroma sample position and the second chroma sample position is determined according to the chroma sampling position information.

Abstract: Methods and apparatus of processing 360-degree virtual reality images are disclosed. According to one method, the method receives coded data for an extended 2D (two-dimensional) frame including an encoded 2D frame with one or more encoded guard bands, wherein the encoded 2D frame is projected from a 3D (three-dimensional) sphere using a target projection, wherein said one or more encoded guard bands are based on a blending of one or more guard bands with an overlapped region when the overlapped region exists. The method then decodes the coded data into a decoded extended 2D frame including a decoded 2D frame with one or more decoded guard bands, and derives a reconstructed 2D frame from the decoded extended 2D frame.

Abstract: A de-blocking method is applied to a reconstructed projection-based frame having a first projection face and a second projection face, and includes obtaining a first spherical neighboring block for a first block with a block edge to be de-blocking filtered, and selectively applying de-blocking to the block edge of the first block for at least updating a portion of pixels of the first block. There is image content discontinuity between a face boundary of the first projection face and a face boundary of the second projection face. The first block is a part of the first projection face, and the block edge of the first block is a part of the face boundary of the first projection face. A region on a sphere to which the first spherical neighboring block corresponds is adjacent to a region on the sphere from which the first projection face is obtained.

Abstract: A luma-based chroma intra-prediction method includes: applying, by a filter circuit with a first weighting table, weighting to reconstructed luma samples to generate a first down-sampled luma sample, wherein the reconstructed luma samples are external to a luma block; computing parameters of a linear model, wherein a pair of the first down-sampled luma sample and a reconstructed chroma sample that is external to a chroma block is involved in computing the parameters of the linear model; and determining a predicted value of a chroma sample included in the chroma block according to the linear model and a second down-sampled luma sample that is derived from the luma block.

Abstract: Methods and apparatus of processing 360-degree virtual reality images are disclosed. According to one method, a 2D (two-dimensional) frame is divided into multiple blocks. The multiple blocks are encoded or decoded using quantization parameters by restricting a delta quantization parameter to be within a threshold for any two blocks corresponding to two neighboring blocks on a 3D sphere. According to another embodiment, one or more guard bands are added to one or more edges that are discontinuous in the 2D frame but continuous in the 3D sphere. Fade-out process is applied to said one or more guard bands to generate one or more faded guard bands. At the decoder side, the reconstructed 2D frame is generated from the decoded extended 2D frame by cropping said one or more decoded faded guard bands or by blending said one or more decoded faded guard bands and reconstructed duplicated areas.

Abstract: Methods and apparatus of processing 360-degree virtual reality (VR360) pictures are disclosed. According to one method, if a leaf coding unit contains one or more face edges, the leaf processing unit is split into sub-processing units along the face edges without the need to signal the partition. In another method, if the quadtree (QT) of binary tree (BT) partition depth for a processing unit has not reached the maximum QT or BT depth, the processing unit is split. If the processing unit contains a horizontal face edge, QT or horizontal BT partition is applied. If the processing unit contains a vertical face edge, QT or vertical BT partition is applied.

Abstract: Method and apparatus of coding 360-degree virtual reality (VR360) pictures are disclosed. According to the method, when a first MV (motion vector) of a target neighboring block for the current block is not available within the 2D projection picture, or when the target neighboring block is not in a same face as the current block: a true neighboring block picture corresponding to the target neighboring block is identified within the 2D projection; if a second MV of the true neighboring block exists, the second MV of the true neighboring block is transformed into a derived MV; and a current MV of the current block is encoded or decoded using the derived MV or one selected candidate in a MV candidate list including the derived MV as an MV predictor.

Abstract: A de-blocking method is applied to a reconstructed projection-based frame having a first projection face and a second projection face, and includes obtaining a first spherical neighboring block for a first block with a block edge to be de-blocking filtered, and selectively applying de-blocking to the block edge of the first block for at least updating a portion of pixels of the first block. There is image content discontinuity between a face boundary of the first projection face and a face boundary of the second projection face. The first block is a part of the first projection face, and the block edge of the first block is a part of the face boundary of the first projection face. A region on a sphere to which the first spherical neighboring block corresponds is adjacent to a region on the sphere from which the first projection face is obtained.

Abstract: A method includes steps of: preparing first and second plates, each first plate having surrounding apertures, each aperture including a first accommodation portion and an outer necking portion, each second plate having surrounding accommodation portions; stacking the first plates by aligning necking portions to form band gaps extending linearly and parallel to each other; stacking two second plates to two opposing terminal portions of the stacked first plates; penetrating metal bars into the aligned first and second accommodation portions by exposing both ends of each metal bar; beetling the necking portions at each band gap so as to locate firmly the corresponding metal bar; positioning a first mold and a second mold to clamp the stacked plate structure; injecting metal slurries into the first and second molds and then solidifying the metal slurries to form two end rings; and, removing the first and second molds to complete a rotor structure.

Abstract: Methods for processing 360-degree virtual reality images are disclosed. According to one method, coding flags for the target block are skipped for inactive blocks at an encoder side or pixels for the target block are derived based on information identifying the target block being the inactive block at a decoder side. According to another method, when a target block is partially filled with inactive pixels, the best predictor is selected using rate-distortion optimization, where distortion associated with the rate-distortion optimization is measured by excluding inactive pixels of the target block. According to another method, the inactive pixels of a residual block are padded with values to achieve the best rate-distortion optimization. According to another method, active pixels of the residual block are rearranged into a smaller block and coding is applied to the smaller block, or shape-adaptive transform coding is applied to the active pixels of the residual block.

Abstract: Methods and apparatus of processing 360-degree virtual reality images are disclosed. According to one method, a 2D (two-dimensional) frame is divided into multiple blocks. The multiple blocks are encoded or decoded using quantization parameters by restricting a delta quantization parameter to be within a threshold for any two blocks corresponding to two neighboring blocks on a 3D sphere. According to another embodiment, one or more guard bands are added to one or more edges that are discontinuous in the 2D frame but continuous in the 3D sphere. Fade-out process is applied to said one or more guard bands to generate one or more faded guard bands. At the decoder side, the reconstructed 2D frame is generated from the decoded extended 2D frame by cropping said one or more decoded faded guard bands or by blending said one or more decoded faded guard bands and reconstructed duplicated areas.

Abstract: A video processing method includes receiving a projection-based frame, and encoding, by a video encoder, the projection-based frame to generate a part of a bitstream. The projection-based frame has a 360-degree content represented by projection faces packed in a 360-degree Virtual Reality (360 VR) projection layout, and there is at least one image content discontinuity boundary resulting from packing of the projection faces. The step of encoding the projection-based frame includes performing a prediction operation upon a current block in the projection-based frame, including: checking if the current block and a spatial neighbor are located at different projection faces and are on opposite sides of one image content discontinuity boundary; and when a checking result indicates that the current block and the spatial neighbor are located at different projection faces and are on opposite sides of one image content discontinuity boundary, treating the spatial neighbor as non-available.

Abstract: A method includes steps of: preparing first and second plates, each first plate having surrounding apertures, each aperture including a first accommodation portion and an outer necking portion, each second plate having surrounding accommodation portions; stacking the first plates by aligning necking portions to form band gaps extending linearly and parallel to each other; stacking two second plates to two opposing terminal portions of the stacked first plates; penetrating metal bars into the aligned first and second accommodation portions by exposing both ends of each metal bar; beetling the necking portions at each band gap so as to locate firmly the corresponding metal bar; positioning a first mold and a second mold to clamp the stacked plate structure; injecting metal slurries into the first and second molds and then solidifying the metal slurries to form two end rings; and, removing the first and second molds to complete a rotor structure.