摘要:
A method for minimizing and optimizing a list of active reference pictures to be used for (forward or backward) inter coding of a current picture, or of a pixel region (e.g., video object) within the current picture. Setting the number of active reference pictures in a list equal to one based upon one or more decisions related to the pixel data and movement between the current picture and one or more reference pictures. Otherwise, minimizing the number of active reference pictures in the list based upon one or more other decisions related to the pixel data and movement between the current picture and one or more reference pictures. Minimizing the number of active reference pictures in a second reference picture list based upon the utilization of reference pictures in the first reference picture list. A video encoder processes data representing a two-dimensional video image which has been produced by a conventional commercially available video camera. The video encoder is adapted to determine, select, and to minimize the number of active reference pictures to be used to inter code a current picture. The bit stream transmitted by the encoder can be decoded by decoders of the related art.
摘要:
A hybrid intra-inter bi-predictive (or multi-predictive) coding mode allows both intraframe (intra) (301 in FIG. 5) and interframe (inter) (302 in FIG. 5) predictions to be combined together for hybrid-encoding a current macroblock or a subblock (310 in FIG. 5). Bi-prediction may be used also in I-pictures, combining two intra predictions that use two different intra prediction directions. A video encoder (700) processes data representing a two-dimensional video image which has been produced by a conventional commercially available video camera. The video encoder is adapted to select, for coding a current macroblock, between an intra encoding mode, an P-frame inter encoding mode, a B-frame bi-predictive inter mode, and a hybrid intra-inter bi-predictive encoding mode. A video decoder (800) receives and decodes a data stream that may contain a block/macroblock encoded in accordance with the hybrid intra-inter bi-predictive encoding mode.
摘要:
There is provided a compression method for handling local brightness variation in video. The compression method estimates the weights from previously encoded and reconstructed neighboring pixels of the current block in the source picture and their corresponding motion predicted (or collocated) pixels in the reference pictures. Since the information is available in both the encoder and decoder for deriving these weights, no additional bits are required to be transmitted.
摘要:
L'invention concerne un procédé et un appareil permettant de réutiliser des données de mouvement disponibles comme prédicteur d'estimation de mouvement pour un codage vidéo. L'appareil comprend un codeur (100) qui code un bloc d'images en déterminant un prédicteur d'estimation de mouvement pour ledit bloc d'images à l'aide de données de mouvement générées antérieurement par un élément autre que le codeur, et en utilisant le prédicteur d'estimation de mouvement dans un processus d'estimation de mouvement destiné à générer un vecteur de mouvement pour le bloc d'images. Le prédicteur d'estimation de mouvement est utilisé à la place d'au moins un prédicteur autrement utilisé dans le processus d'estimation de mouvement. Le prédicteur est l'un quelconque des éléments suivants: un prédicteur à fenêtre de recherche, un prédicteur temporel et un prédicteur de type bloc.
摘要:
Individual pixels in an image block undergo blending with film grain from a film grain block randomly selected from among a pool of previously established film grain blocks in accordance with a luma characteristic of the image block. Prior to blending, the selected film grain block undergoes deblocking by a deblocking filter ( 28 ). Following blending, a clipper clips the individual pixels prior to display. The pool of film grain blocks is created by scaling a set of film grain patterns in accordance with at least one parameter of a film grain information message that accompanies the image block.
摘要:
A method and apparatus are provided for motion estimation using combined reference bi-prediction. The apparatus includes an encoder (200) for encoding a multi-prediction picture from a combination of two or more reference pictures by respectively predicting a motion vector for a particular one of the two or more reference pictures in a motion estimation process while initializing motion vectors for remaining ones of the two or more reference pictures to a predefined value for use by the motion estimation process.
摘要:
There are provided a method and apparatus for adaptive Group of Pictures structure selection. The apparatus includes an encoder for encoding a video sequence using a Group of Pictures structure by performing, for each Group of Pictures for the video sequence, picture coding order selection, picture type selection, and reference picture selection. The selections are based upon a Group of Pictures length.
摘要:
There are provided video encoders, video decoders, and corresponding encoding and decoding methods for video data for a picture, wherein the video data has local brightness variation. The video encoder includes an encoder (200) for intercoding the video data using a localized weighted function to determine weights for the local brightness variation. The weights for the localized weighted function are derived without explicit coding.
摘要:
Simulation of film grain in an image can occur by compressing a video image, then transmitting compressed video together with a message containing at least one parameter indicative of the original film grain, to a decoder, and restoring the original grainy appearance of images by having the decoder simulating film grain based on the content of the film grain message. To improve efficiency, one or more parameters of film grain information undergo scaling in accordance with a target pixel block size for pixel blocks in the image. Such scaling allows for the use of conventional circuitry for performing block-based operations in connection with the film grain simulation.