A method for optimizing a second coding is provided. The method includes: Setting a quantization parameter of a start frame of a video sequence according to a range of an input quantization parameter QP.sub.0 of a coder; performing first coding with a simplified method, and calculating a frame-level temporal impact factor k.sub.i of a current frame and a block-level temporal impact factor k.sub.B,j of all 16×16 pixel blocks in the current frame; restoring reference list information of the coder after the first coding is completed, and then determining whether a scene is switched; and performing the second coding by setting quantization parameters with different strategies according to whether the scene is switched.

A temporal domain rate distortion optimization based on video content characteristic and QP-λ correction provides the temporal domain rate distortion optimization based on the video content characteristic and the QP-λ correction for a new generation encoder AV1, wherein according to a previous temporal domain dependency relationship under an HEVC-RA coding structure, a feature of the new generation encoder AV1 and a video sequence feature, an aggregation distortion of a current coding unit and an affected future coding unit is estimated and to propagation factor of the current coding unit in a temporal domain distortion propagation model is calculated by constructing a temporal domain distortion propagation chain, wherein a Lagrange multiplier is adjusted through a more accurate propagation factor to realize a temporal domain dependency rate distortion optimization, and a relationship of QP-λ is re-corrected and an I frame is adjusted to achieve a better coding effect

A data transmitting method includes generating multiple channels of encoded data by encoding same data to be encoded according to a plurality of bit rates and selecting encoded data to be transmitted from the multiple channels of encoded data according to a channel bandwidth of a transmission channel. The encoded data to be transmitted is one of the multiple channels of encoded data that matches the channel bandwidth.

A data transmitting method includes generating multiple channels of encoded data by encoding same data to be encoded according to a plurality of bit rates and selecting encoded data to be transmitted from the multiple channels of encoded data according to a channel bandwidth of a transmission channel. The encoded data to be transmitted is one of the multiple channels of encoded data that matches the channel bandwidth.

A method of perceptual video coding based on face detection is provided. The method includes calculating a bit allocation scheme for coding a light field video based on a saliency map of the face, calculating an LCU level Lagrange multiplier for coding a light field video based on a saliency map of the face and calculating an LCU level quantization parameter for coding a light field video based on a saliency map of the face.

Systems, methods, and articles of manufacture are disclosed that enable the compression of depth data and real-time reconstruction of high-quality light fields. In one aspect, spatial compression and decompression of depth images is divided into the following stages: generating a quadtree data structure for each depth image captured by a light field probe and difference mask associated with the depth image, with each node of the quadtree approximating a corresponding portion of the depth image data using an approximating function; generating, from the quadtree for each depth image, a runtime packed form that is more lightweight and has a desired maximum error; and assembling multiple such runtime packed forms into per-probe stream(s); and decoding at runtime the assembled per-probe stream(s). Further, a block compression format is disclosed for approximating depth data by augmenting the block compression format 3DC+(BC4) with a line and two pairs of endpoints.

Systems, methods, and articles of manufacture are disclosed that enable the compression of depth data and real-time reconstruction of high-quality light fields. In one aspect, spatial compression and decompression of depth images is divided into the following stages: generating a quadtree data structure for each depth image captured by a light field probe and difference mask associated with the depth image, with each node of the quadtree approximating a corresponding portion of the depth image data using an approximating function; generating, from the quadtree for each depth image, a runtime packed form that is more lightweight and has a desired maximum error; and assembling multiple such runtime packed forms into per-probe stream(s); and decoding at runtime the assembled per-probe stream(s). Further, a block compression format is disclosed for approximating depth data by augmenting the block compression format 3DC+(BC4) with a line and two pairs of endpoints.

Disclosed herein are a point cloud data transmission method including encoding point cloud data, and transmitting a bitstream containing the point cloud data, and a point cloud data reception method including receiving a bitstream containing point cloud data, and decoding the point cloud data.

A prediction set determining section selects a prediction set from a prediction set group including a plurality of prediction sets having different combinations of prediction modes corresponding to different prediction directions. Further, a prediction mode determining section selects a prediction mode from the prediction set thus selected. An entropy encoding section encodes the prediction set thus selected, the prediction mode thus selected, and residual data between an input image and a predicted image formed on the basis of the prediction set and the prediction mode. This allows an image encoding device to carry out predictions from more various angles, thereby improving prediction efficiency.

A prediction set determining section selects a prediction set from a prediction set group including a plurality of prediction sets having different combinations of prediction modes corresponding to different prediction directions. Further, a prediction mode determining section selects a prediction mode from the prediction set thus selected. An entropy encoding section encodes the prediction set thus selected, the prediction mode thus selected, and residual data between an input image and a predicted image formed on the basis of the prediction set and the prediction mode. This allows an image encoding device to carry out predictions from more various angles, thereby improving prediction efficiency.