RECORDING MEDIUM HAVING RECORDED THEREON CODED INFORMATION USING PLUS AND/OR MINUS ROUNDING OF IMAGES

• US 20110007810A1
• Filed: 09/20/2010
• Published: 01/13/2011
• Est. Priority Date: 06/09/1997
• Status: Active Grant

• Current Assignee: Yuichiro Nakaya
• Original Assignee: Yuichiro Nakaya
• Inventors: NAKAYA, Yuichiro
• Granted Patent: US 7,929,783 B2
• Time in Patent Office: Days
• US Class Current: 375/240.16
• CPC Class Codes: G06T 7/223 using block-matching
• CPC Class Codes: G06T 7/262 using transform domain methods, e.g. Fourier domain methods
• CPC Class Codes: G06T 9/004 Predictors, e.g. intraframe, interframe coding
• CPC Class Codes: H04N 19/105 Selection of the reference unit for prediction within a chosen coding or prediction mode, e.g. adaptive choice of position and number of pixels used for prediction
• CPC Class Codes: H04N 19/114 Adapting the group of pictures [GOP] structure, e.g. number of B-frames between two anchor frames H04N19/107 takes precedence
• CPC Class Codes: H04N 19/115 Selection of the code volume for a coding unit prior to coding
• CPC Class Codes: H04N 19/117 Filters, e.g. for pre-processing or post-processing sub-band filter banks H04N19/635
• CPC Class Codes: H04N 19/124 Quantisation
• CPC Class Codes: H04N 19/126 Details of normalisation or weighting functions, e.g. normalisation matrices or variable uniform quantisers
• CPC Class Codes: H04N 19/127 Prioritisation of hardware or computational resources
• CPC Class Codes: H04N 19/139 Analysis of motion vectors, e.g. their magnitude, direction, variance or reliability
• CPC Class Codes: H04N 19/159 Prediction type, e.g. intra-frame, inter-frame or bidirectional frame prediction
• CPC Class Codes: H04N 19/16 for a given display mode, e.g. for interlaced or progressive display mode
• CPC Class Codes: H04N 19/172 the region being a picture, frame or field
• CPC Class Codes: H04N 19/176 the region being a block, e.g. a macroblock
• CPC Class Codes: H04N 19/177 the unit being a group of pictures [GOP]
• CPC Class Codes: H04N 19/18 the unit being a set of transform coefficients
• CPC Class Codes: H04N 19/182 the unit being a pixel
• CPC Class Codes: H04N 19/184 the unit being bits, e.g. of the compressed video stream
• CPC Class Codes: H04N 19/186 the unit being a colour or a chrominance component
• CPC Class Codes: H04N 19/19 : using optimisation based on Lagrange multipliers
• CPC Class Codes: H04N 19/44 : Decoders specially adapted therefor, e.g. video decoders which are asymmetric with respect to the encoder
• CPC Class Codes: H04N 19/45 : performing compensation of the inverse transform mismatch, e.g. Inverse Discrete Cosine Transform [IDCT] mismatch
• CPC Class Codes: H04N 19/46 : Embedding additional information in the video signal during the compression process H04N19/517, H04N19/68, H04N19/70 take precedence
• CPC Class Codes: H04N 19/50 : using predictive coding H04N19/61 takes precedence
• CPC Class Codes: H04N 19/51 : Motion estimation or motion compensation
• CPC Class Codes: H04N 19/513 : Processing of motion vectors
• CPC Class Codes: H04N 19/52 : by predictive encoding
• CPC Class Codes: H04N 19/521 : for estimating the reliability of the determined motion vectors or motion vector field, e.g. for smoothing the motion vector field or for correcting motion vectors
• CPC Class Codes: H04N 19/523 : with sub-pixel accuracy
• CPC Class Codes: H04N 19/547 : Motion estimation performed in a transform domain
• CPC Class Codes: H04N 19/573 : Motion compensation with multiple frame prediction using two or more reference frames in a given prediction direction
• CPC Class Codes: H04N 19/577 : Motion compensation with bidirectional frame interpolation, i.e. using B-pictures
• CPC Class Codes: H04N 19/587 : involving temporal sub-sampling or interpolation, e.g. decimation or subsequent interpolation of pictures in a video sequence
• CPC Class Codes: H04N 19/59 : involving spatial sub-sampling or interpolation, e.g. alteration of picture size or resolution
• CPC Class Codes: H04N 19/597 : specially adapted for multi-view video sequence encoding
• CPC Class Codes: H04N 19/61 : in combination with predictive coding
• CPC Class Codes: H04N 19/625 : using discrete cosine transform [DCT]
• CPC Class Codes: H04N 19/86 : involving reduction of coding artifacts, e.g. of blockiness
• CPC Class Codes: H04N 19/90 : using coding techniques not provided for in groups H04N19/10-H04N19/85, e.g. fractals
• CPC Class Codes: H04N 19/94 : Vector quantisation

Abstract

Image decoding method including: receiving an encoded bitstream including information of I and P frames; and executing motion compensation by synthesizing a predicted image of a current frame using motion vector information included in the encoded bitstream and a previously-decoded reference image. The motion compensation includes calculating intensity values at points where no pixels actually exist by bilinear interpolation performable using a positive rounding method and a negative rounding method; wherein the bilinear interpolation is performed using the rounding method specified by rounding method information included in the encoded bitstream of the current frame when the current frame is a P frame; wherein the rounding method information is included in a header section of the coded information of the current frame; and wherein the rounding method information is not received from the encoded bitstream of the current frame when the current frame is an I frame.

Claims

1. An image decoding method comprising the steps of:

receiving an encoded bitstream including information of I and P frames; and

executing motion compensation by synthesizing a predicted image of a current frame using motion vector information included in the encoded bitstream and a reference image which is a previously decoded image;

wherein said motion compensation includes calculating intensity values at points where no pixels actually exist in the reference image by bilinear interpolation, the bilinear interpolation being performable using a positive rounding method and a negative rounding method;

wherein the bilinear interpolation is performed using the rounding method specified by rounding method information included in the encoded bitstream of the current frame when the current frame is a P frame;

wherein the rounding method information is included in a header section of the coded information of the current frame; and

wherein the rounding method information is not received from the encoded bitstream of the current frame when the current frame is an I frame.