An image encoding device and a method, and an image decoding device and a method that are designed to improve encoding efficiency in IntraBC. A screen is divided into four slices (Slices #0 through #3). In a case where reference to a different slice is prohibited, the range that can be referred to from the current CTU in Slice #2 is only the decoded portion in Slice #2, and therefore, any block in Slice #1 cannot be referred to, for example. In the case of the present technology, on the other hand, decoded different slices (Slice #0 and Slice #1)are included in the referable range, and accordingly, a block in Slice #1 can be referred to from the current CTU in Slice #2.

Embodiments provide methods and devices (encoder and/or decoder) of coding a picture. A History Based Motion Vector Prediction (HMVP) list for a current Coding Tree Unit (CTU) row within a tile of a picture is initialized and a CTU of the current CTU row is processed based on the initialized HMVP list.

Technique for initialization of encoders and decoders. In some cases, the decoder receives a slice and identifies if the slice is either a forward predicted B-slice or a backward predicted B-slice, and not both a forward and backward predicted B-slice, and based upon this identification initializes, using a P-slice technique, a context associated with the slice.

Provided is a video decoding method including: generating coding units by splitting at least one of a height and a width of a largest coding unit having a first size; based on whether a height or a width of a non-square first coding unit including an outer boundary of an image, among the coding units, is greater than a maximum transform size, determining whether it is allowed to generate two second coding units by splitting at least one of the height and the width of the first coding unit; and decoding the second coding units generated from the first coding unit.

An example disclosed system may include a hardware video encoding pipeline (HVEP), the HVEP that includes a prediction module that generates, using a primary prediction mode, a primary encode of a portion of a video stream, and using a secondary prediction mode, a secondary encode of the portion of the video stream. The HVEP may also include (1) a rate-distortion optimization (RDO) module that determines a primary cost associated with the primary encode and a secondary cost associated with the secondary encode, (2) a quality metric (QM) module that determines a primary QM associated with the primary encode and a secondary QM associated with the secondary encode, and (3) a decision module that selects, for an encoding of the video stream, at least one of the primary prediction mode and the secondary prediction mode based on the primary cost, the secondary cost, the primary QM, and the secondary QM.

An example disclosed system may include a hardware video encoding pipeline (HVEP), the HVEP that includes a prediction module that generates, using a primary prediction mode, a primary encode of a portion of a video stream, and using a secondary prediction mode, a secondary encode of the portion of the video stream. The HVEP may also include (1) a rate-distortion optimization (RDO) module that determines a primary cost associated with the primary encode and a secondary cost associated with the secondary encode, (2) a quality metric (QM) module that determines a primary QM associated with the primary encode and a secondary QM associated with the secondary encode, and (3) a decision module that selects, for an encoding of the video stream, at least one of the primary prediction mode and the secondary prediction mode based on the primary cost, the secondary cost, the primary QM, and the secondary QM.

Methods and apparatuses of encoding a video stream encoded using video point cloud coding include obtaining a plurality of frames including a first frame and remaining frames, wherein each frame of the plurality of frames is packed with a corresponding plurality of patches; grouping the remaining frames into a first group and a second group, wherein frames grouped into same group are temporally neighboring; processing the first frame; parallel processing frames in the first group after the first frame is processed; and generating an encoded video stream based on the processed first frame and the processed frames in the first group, wherein at least one frame of the first group depends from the first frame.

An image decoding method and apparatus according to an embodiment may extract, from a bitstream, a quantization coefficient generated through core transformation, secondary transformation, and quantization; generate an inverse-quantization coefficient by performing inverse quantization on the quantization coefficient; generate a secondary inverse-transformation coefficient by performing secondary inverse-transformation on a low frequency component of the inverse-quantization coefficient, the secondary inverse-transformation corresponding to the secondary transformation; and perform core inverse-transformation on the secondary inverse-transformation coefficient, the core inverse-transformation corresponding to the core transformation.

An image decoding method and apparatus according to an embodiment may extract, from a bitstream, a quantization coefficient generated through core transformation, secondary transformation, and quantization; generate an inverse-quantization coefficient by performing inverse quantization on the quantization coefficient; generate a secondary inverse-transformation coefficient by performing secondary inverse-transformation on a low frequency component of the inverse-quantization coefficient, the secondary inverse-transformation corresponding to the secondary transformation; and perform core inverse-transformation on the secondary inverse-transformation coefficient, the core inverse-transformation corresponding to the core transformation.

A system comprises an encoder configured to compress attribute information for a point cloud and/or a decoder configured to decompress compressed attribute information for the point cloud. Attribute values for at least one starting point are included in a compressed attribute information file and attribute correction values used to correct predicted attribute values are included in the compressed attribute information file. Attribute values are predicted based, at least in part, on attribute values of neighboring points and distances between a particular point for whom an attribute value is being predicted and the neighboring points. The predicted attribute values are compared to attribute values of a point cloud prior to compression to determine attribute correction values. A decoder follows a similar prediction process as an encoder and corrects predicted values using attribute correction values included in a compressed attribute information file.