摘要:
Disclosed is an image decoding method including a step of variable-length-decoding coded data multiplexed into a bitstream to acquire compressed data associated with a coding block, a reference image restriction flag indicating whether or not to restrict a significant reference image area which is an area on a reference image which can be used for the motion-compensated prediction, and motion information and a motion-compensated prediction step of carrying out a motion-compensated prediction process on the coding block on the basis of the motion information to generate a prediction image, in which the motion-compensated prediction step includes a step of when the prediction image includes a pixel located outside the significant reference image area, carrying out a predetermined extending process to generate the prediction image on the basis of the reference image restriction flag by using the motion information.
摘要:
A method and system for predicting a moving picture to be implemented in an encoder is provided. The system includes a plurality of reference picture memory areas for storing reference pictures to be used for prediction and a prediction generation section that includes a motion compensator and memory updater. The motion compensator receives a parameter representing the motion between an image to be predicted and a reference picture stored in the reference picture memory area and a parameter representing the reference picture memory area to be used for prediction, and generates a predicted image by using the reference picture stored in the reference picture memory area indicated by the parameter representing the reference picture memory area. The memory updater carries out dynamic allocation of reference picture memory areas required for prediction and judges whether to store new reference pictures additionally.
摘要:
An image decoding device and method analyzes a parameter of the encoded bit stream to restore a 1-bit information to indicate that temporal distance between any two successive video frames to be displayed is constant in the video sequence, the 1-bit information being analyzed prior to a decoding process for a data area representing the video frames, A VOP decoder decodes a VOP that is image data serving as an encoding unit of video object and a VOL header analyzing part decodes a VOP rate flag, contained in encoded form in a header information part of a VOL layer composed of several VOPs, for indicating that a display rate in the VOL of the VOP to be decoded by the VOP decoder is a fixed rate by the VOP rate flag only.
摘要:
When an intra prediction parameter indicates a horizontal prediction process, an intra prediction unit adds a value proportional to a change in a horizontal direction of the luminance values of pixels adjacent to the top of each block, which is a unit for prediction process of a coding block, to the luminance value of a pixel adjacent to the left of the block to set a result of the addition as a predicted value of a prediction image, whereas when the intra prediction parameter indicates a vertical prediction process, the intra prediction unit adds a value proportional to a change in a vertical direction of the luminance values of pixels adjacent to the left of the block to the luminance value of the pixel adjacent to the top of the block to set the result of the addition as a predicted value of the prediction image.
摘要:
When carrying out an intra-frame prediction process to generate an intra prediction image by using an already-encoded image signal in a frame, an intra prediction part 4 refers to a table for filter selection to select a filter from one or more filters which are prepared in advance according to the states of various parameters associated with the encoding of a target block to be filtered, and carries out a filtering process on the prediction image by using the filter. As a result, prediction errors locally occurring can be reduced, and the image quality can be improved.
摘要:
To achieve an encoding system including a highly efficient prediction performed in response to the content of a scene, a significance, and a motion characteristic of a moving picture and the like, a reference memory, a motion compensator receiving a parameter representing the motion of a prediction picture segment for generating a predicted picture by using arbitrary data stored in the memory based upon the parameter, and memory update unit that updates picture data in memory and controls the capacity of the memory, are provided.
摘要:
An image encoder including: a predicted-image generating unit that generates a predicted image in accordance with a plurality of prediction modes indicating predicted-image generating methods; a prediction-mode judging unit that evaluates prediction efficiency of a predicted image outputted from the predicted-image generating unit to judge a predetermined prediction mode; and an encoding unit that subjects an output of the prediction-mode judging unit to variable-length encoding. The prediction-mode judging unit judges, on the basis of a predetermined control signal, which one of a common prediction mode and a separate prediction mode is used for respective color components forming the input image signal, and multiplexes information on the control signal on a bit stream, multiplexes, when the common prediction mode is used, common prediction mode information on the bit stream, and multiplexes, when the common prediction mode is not used, prediction mode information for each of the color components on the bit stream.
摘要:
A macro block size determining unit 1 determines the size of each macro block on a frame-by-frame basis. A macro block dividing unit 2 divides an inputted image into macro blocks each having the size determined by the macro block size determining unit 1. A macro block coding unit 3 determines a coding mode for each of the macro blocks divided by the macro block dividing unit 2, and codes pixel values in each of the macro blocks in the determined coding mode.
摘要:
Encoding and decoding are uniformly carried out for a plurality of chroma formats. Based on a control signal for providing a chroma format type of an input moving image signal, in the case of a chroma format of 4:2:0 or 4:2:2, a first intra prediction mode deciding unit and a first intra prediction image generation unit are applied to a luminance component of the input moving image signal, and a second intra prediction mode deciding unit and a second intra prediction image generation unit are applied to a chrominance component. In the case of a chroma format of 4:4:4, the first intra prediction mode deciding unit and the first intra prediction image generation unit are applied to all color components to carry out encoding, and a variable length encoding unit multiplexes the control signal as encoding data to be applied to a moving image sequence unit on a bit stream.
摘要:
An encoding device includes a color component separating unit for separating an input bit stream for the respective color components, a block dividing unit for dividing an input color component signal into blocks to generate a signal of an encoding unit area, a predicted image generating unit for generating a predicted image for the signal, a determining unit for determining a prediction mode used for encoding according to a prediction efficiency of the predicted image, a prediction error encoding unit for encoding a difference between the predicted image corresponding to the prediction mode determined by the determining unit and the input color component signal, and an encoding unit for variable length-coding the prediction mode, an output from the prediction error encoding unit, and a color component identification flag indicating the color component to which the input bit stream belongs as a result of the color component separation.