Method for deriving a temporal predictive motion vector, and apparatus using the method

• US 10,523,967 B2
• Filed: 09/06/2012
• Issued: 12/31/2019
• Est. Priority Date: 09/09/2011
• Status: Active Grant

• Current Assignee: KT Corporation
• Original Assignee: KT Corporation
• Inventors: Lee, Bae Keun, Kwon, Jae Cheol, Kim, Joo Young
• Primary Examiner(s): Bailey, Frederick D
• Application Number:
  US14/002,444
• Publication Number:
  US 20130343461A1
• Time in Patent Office: 2,672 Days
• Field of Search: 37524016
• 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 19/136 Incoming video signal characteristics or properties
• CPC Class Codes: H04N 19/167 Position within a video image, e.g. region of interest [ROI]
• 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 19/52 by predictive encoding
• CPC Class Codes: H04N 19/61 in combination with predictive coding

Abstract

Disclosed are a method for deriving a temporal predictive motion vector, and an apparatus using the method. An image decoding method may comprise the steps of: determining whether or not a block to be predicted is brought into contact with a boundary of a largest coding unit (LCU); and determining whether or not a first call block is available according to whether or not the block to be predicted is brought into contact with the boundary of the LCU. Accordingly, unnecessary memory bandwidth may be reduced, and implementation complexity may also be reduced.

Claims

1. A method of decoding a video signal with a decoding apparatus, comprising:

deriving inverse-quantized residual coefficients by inverse-quantizing residual coefficients relating to a current block;

deriving residual samples by performing an inverse-transform for the inverse-quantized residual coefficients of the current block;

obtaining prediction samples of the current block by performing inter prediction or intra prediction; and

reconstructing the current block by using the residual samples and the prediction samples;

wherein when the prediction samples of the current block are obtained by performing inter prediction, obtaining the prediction samples of the current block comprises;

extracting a collocated picture index relating to a collocated picture from a bitstream;

selecting, based on the collocated picture index, the collocated picture of a current block from a reference picture list, the collocated picture comprising a temporal candidate block which is used to derive a motion vector of the current block;

determining the temporal candidate block in the collocated picture;

obtaining a temporal prediction motion vector by scaling a motion vector of the temporal candidate block;

constructing a merging candidate list including a plurality of merging candidates, the plurality of merging candidates including the temporal candidate block;

obtaining a motion vector and a reference picture index of the current block based on the merging candidate list; and

obtaining prediction samples of the current block by using the motion vector and the reference picture index of the current block;

wherein the residual samples are obtained by using a discrete cosine transform (DCT) or a discrete sine transform (DST),

wherein either discrete cosine transform (DCT) or discrete sine transform (DST) is selectively performed based on a prediction method and size of the current block,

wherein the prediction method is either an inter prediction method or an intra prediction method, and

wherein when the prediction samples of the current block are obtained by performing intra prediction, the current block is one of plural prediction blocks which are obtained by partitioning a coding block, and wherein the coding block is partitioned into the plural prediction blocks only if the coding block is a smallest coding block.

2. The method of claim 1, wherein the temporal prediction motion vector is obtained by scaling the motion vector of the temporal candidate block based on both a first temporal distance and a second temporal distance, the first temporal distance being a temporal distance between a current picture including the current block and the reference picture of the current block, and the second temporal distance being a temporal distance between the collocated picture and a reference picture of the temporal candidate block.

3. The method of claim 1, wherein when the prediction samples of the current block are obtained by performing intra prediction, the method further comprises:

obtaining reference samples of the current block based on neighboring samples adjacent to the current block; and

applying a smoothing filter to the reference samples based on an intra prediction mode of the current block and a filter information provided from a video encoder.

4. The method of claim 3, applying the smoothing filter comprises:

determining whether to apply the smoothing filter to the reference samples based on the intra prediction mode of the current block; and

selecting one of a plurality of smoothing filters based on the filter information when the smoothing filter is applied to the reference samples.

5. The method of claim 1, wherein the intra prediction is performed on a transform block basis when a size of the prediction block is different from a size of the transform block.