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 video processing method includes: obtaining a plurality of projection faces from an omnidirectional content of a sphere, wherein the omnidirectional content of the sphere is mapped onto the projection faces via cubemap projection, and the projection faces comprise a first projection face; obtaining, by a re-sampling circuit, a first re-sampled projection face by re-sampling at least a portion of the first projection face through non-uniform mapping; generating a projection-based frame according to a projection layout of the cubemap projection, wherein the projection-based frame comprises the first re-sampled projection face packed in the projection layout; and encoding the projection-based frame to generate a part of a bitstream.

Abstract: A video decoding method includes decoding a part of a bitstream to generate a decoded frame. The decoded frame is a projection-based frame that comprises at least one projection face and at least one guard band packed in a projection layout. At least a portion of a 360-degree content of a sphere is mapped to the at least one projection face via projection. The decoded frame is in a 4:2:0 chroma format or a 4:2:2 chroma format, and a guard band size of each of the at least one guard band is equal to an even number of luma samples.

Abstract: A cube-based projection method includes generating pixels of different square projection faces associated with a cube-based projection of a 360-degree image content of a sphere. Pixels of a first square projection face are generated by utilizing a first mapping function set. Pixels of a second square projection face are generated by utilizing a second mapping function set. The different square projection faces include the first square projection face and the second square projection face. The second mapping function set is not identical to the first mapping function set.

Abstract: A video decoding method includes: decoding a part of a bitstream to generate a decoded frame, and parsing at least one syntax element from the bitstream. The decoded frame is a projection-based frame that includes projection faces packed in a cube-based projection layout. At least a portion of a 360-degree content of a sphere is mapped to the projection faces via cube-based projection. The at least one syntax element is indicative of a guard band configuration of the projection-based frame.

Abstract: A video encoding method includes: encoding a projection-based frame to generate a part of a bitstream, wherein at least a portion of a 360-degree content of a sphere is mapped to projection faces via cube-based projection, and the projection-based frame has the projection faces packed in a cube-based projection layout; and signaling at least one syntax element via the bitstream, wherein said at least one syntax element is associated with a mapping function that is employed by the cube-based projection to determine sample locations for each of the projection faces.

Abstract: A video decoding method includes decoding a part of a bitstream to generate a decoded frame, and parsing at least one syntax element from the bitstream. The decoded frame is a projection-based frame that has projection faces packed in a cube-based projection layout. At least a portion of a 360-degree content of a sphere is mapped to the projection faces via cube-based projection.

Abstract: Methods and apparatus of video coding for 3D video data are disclosed. According to one method, the gradients of the geometry frame are derived. A reconstructed point cloud is reconstructed using the geometry frame. One or more candidate holes in the reconstructed point cloud are filled based on the gradients of the geometry frame. According to another method of encoding for 3D video data, candidate hole locations in a geometry frame, patch or layer are determined. Source points projected to the candidate hole locations are grouped to generate grouped points. The grouped points are removed from an original patch containing the grouped points.

Abstract: An exemplary video processing method includes: receiving an omnidirectional content corresponding to a sphere; obtaining a plurality of projection faces from the omnidirectional content of the sphere according to a pyramid projection; creating at least one padding region; and generating a projection-based frame by packing the projection faces and the at least one padding region in a pyramid projection layout. The projection faces packed in the pyramid projection layout include a first projection face. The at least one padding region packed in the pyramid projection layout includes a first padding region. The first padding region connects with at least the first projection face, and forms at least a portion of one boundary of the pyramid projection layout.

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: 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 an omnidirectional content corresponding to a sphere, generating a projection-based frame according to at least the omnidirectional content and a segmented sphere projection (SSP) format, 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 a first circular projection face, a second circular projection face, and at least one rectangular projection face packed in an SSP layout. A north polar region of the sphere is mapped onto the first circular projection face. A south polar region of the sphere is mapped onto the second circular projection face. At least one non-polar ring-shaped segment between the north polar region and the south polar region of the sphere is mapped onto said at least one rectangular projection face.

Abstract: Methods and apparatus of processing spherical images related to segmented sphere projection (SSP) are disclosed. According to one method, a North Pole region of the spherical image is projected to a first circular image and a South Pole region of the spherical image is projected to a second circular image using a mapping process selected from a mapping group comprising equal-area mapping, non-uniform mapping and cubemap mapping. Methods and apparatus of processing spherical images related to rotated sphere projection (RSP) are also disclosed. According to this method, the spherical image is projected into a first part of rotated sphere projection corresponding to a ?×? region of the spherical image and a second part of rotated sphere projection corresponding to a remaining part of the spherical image using equal-area mapping.

Abstract: A video processing method includes: receiving an omnidirectional image/video content corresponding to a viewing sphere, generating a sequence of projection-based frames according to the omnidirectional image/video content and a viewport-based cube projection layout, and encoding the sequence of projection-based frames to generate a bitstream. Each projection-based frame has a 360-degree image/video content represented by rectangular projection faces packed in the viewport-based cube projection layout. The rectangular projection faces include a first rectangular projection face, a second rectangular projection face, a third rectangular projection face, a fourth rectangular projection face, a fifth rectangular projection face, and a sixth rectangular projection face split into partial rectangular projection faces.

Abstract: A video processing method includes: obtaining a plurality of square projection faces from an omnidirectional content of a sphere according to a cube-based projection, scaling the square projection faces to generate a plurality of scaled projection faces, respectively, creating at least one padding region, generating a projection-based frame by packing the scaled projection faces and said at least one padding region in a projection layout of the cube-based projection, and encoding the projection-based frame to generate a part of a bitstream.

Abstract: A cube-based projection method includes generating pixels of different square projection faces associated with a cube-based projection of a 360-degree image content of a sphere. Pixels of a first square projection face are generated by utilizing a first mapping function set. Pixels of a second square projection face are generated by utilizing a second mapping function set. The different square projection faces include the first square projection face and the second square projection face. The second mapping function set is not identical to the first mapping function set.

Abstract: A video processing method includes obtaining projection face(s) from an omnidirectional content of a sphere, and obtaining a re-sampled projection face by re-sampling at least a portion of a projection face of the projection face(s) through non-uniform mapping. The omnidirectional content of the sphere is mapped onto the projection face(s) via a 360-degree Virtual Reality (360 VR) projection. The projection face has a first source region and a second source region. The re-sampled projection face has a first re-sampled region and a second re-sampled region. The first re-sampled region is derived from re-sampling the first source region with a first sampling density. The second re-sampled region is derived from re-sampling the second source region with a second sampling density that is different from the first sampling density.

Abstract: A video processing method includes: obtaining a plurality of projection faces from an omnidirectional content of a sphere, wherein the omnidirectional content of the sphere is mapped onto the projection faces via cubemap projection, and the projection faces comprise a first projection face; obtaining, by a re-sampling circuit, a first re-sampled projection face by re-sampling at least a portion of the first projection face through non-uniform mapping; generating a projection-based frame according to a projection layout of the cubemap projection, wherein the projection-based frame comprises the first re-sampled projection face packed in the projection layout; and encoding the projection-based frame to generate a part of a bitstream.

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.