Video encoding method and apparatus and video decoding method and apparatus

Abstract

A video encoding method includes extracting at least one reference macroblock from each of a plurality of reference frames to generate a plurality of reference macroblocks, computing a linear sum of the reference macroblocks using weighting factors to generate a predictive macroblock, generating a motion vector between the video macroblock and the reference macroblock corresponding to the predictive macroblock, generating a prediction error signal between the predictive macroblock and the video macroblock, and encoding the prediction error signal, a first index indicating the plurality of reference frames, a second index indicating the weighting factors and the motion vector.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is a Division of U.S. application Ser. No. 10 / 409,068, filed Apr. 9, 2003, the entire contents of which is incorporated herein by reference. [0002] This application is based upon and claims the benefit of priority from the prior Japanese Patent Applications No. 2002-108102, filed Apr. 10, 2002; and No. 2002-341239, filed Nov. 25, 2002, the entire contents of both of which are incorporated herein by reference.BACKGROUND OF THE INVENTION [0003] 1. Field of the Invention [0004] The present invention relates to a video encoding method and apparatus and a video decoding method and apparatus which use a motion compensation predictive inter-frame encoding. [0005] 2. Description of the Related Art [0006] As video compression encoding techniques, MPEG-1 (ISO / IEC11172-2), MPEG-2 (ISO / IEC13818-2), MPEG-4 (ISO / IEC14496-2), and the like have been widely used. In these video encoding schemes, encoding is performed by a combination of...

AI Technical Summary

Benefits of technology

This approach enhances prediction efficiency and reduces encoding and decoding costs by optimizing the encoding of fading pictures, leading to improved picture quality and lower overhead in encoded data.

Problems solved by technology

With regard to temporal enlargement / reduction and rotation of pictures or temporal variations in signal amplitude such as fade-in and fade-out, however, high prediction efficiency cannot always be obtained.

In encoding at a constant bit rate, if such pictures from which high prediction efficiency cannot be obtained are input, a great deterioration in picture quality may occur.

In encoding at a variable bit rate, a large code amount is consumed for pictures with poor prediction efficiency to suppress deterioration in picture quality, resulting in an increase in total code amount.

This requires an enormous amount of transformation computation.

This leads to an enormous amount of encoding computation or an enormous increase in hardware cost and the like.

In addition, a transformation parameter itself must be encoded as well as a prediction residual error, and hence the encoded data becomes enormous.

In addition, inverse affine transformation is required at the time of decoding, resulting in a great amount of decoding computation or a very high hardware cost.

As described above, in the conventional video encoding methods such as MPEGs, sufficient prediction efficiency cannot be obtained with respect to temporal changes in video other than translations.

In addition, in the video encoding and decoding method using affine transformation, although prediction efficiency itself can be improved, the overhead for encoded data increases and the encoding and decoding costs greatly increase.

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