Digital video signal coding apparatus and method, and coded video signal decoding apparatus and method

A digital video signal coding method, comprising the steps of:

• forming the second hierarchical video signal having lower resolution than said first hierarchical video signal based on said first hierarchical video signal;
• predicting said first hierarchical video signal from said second hierarchical video signal;
• calculating the first predictive residue by obtaining the differential between said hierarchy predicted video signal and said first hierarchical video signal to be predicted;
• detecting a motion vector between the current video signal and the video signal of one or "n" frames before said current video signal;
• motion-compensation-predicting said current video signal from said video signal of one or "n" frames before based on said motion vector;
• calculating the second predictive residue by obtaining the differential between said motion compensation predicted video signal and the current video signal to be predicted;
• and
• transmitting the predictive residue, said second hierarchical video signal and/or said motion vector;
• wherein
• said predictive residue to be transmitted is obtained by executing said hierarchy prediction step and said hierarchy predictive residue calculating step, and said motion compensated prediction step and said motion compensation predictive residue calculating step in parallel or in series.

A coded video signal decoding apparatus, wherein:

• a second hierarchical video signal having lower resolution than a first hierarchical video signal is formed;
• the motion vector between the current video signal and the video signal one or "n" frames before said current video signal is detected;
• the video signal corresponding to said first hierarchy is detected from said second hierarchical video signal;
• the current video signal is motion-compensation-predicted from the video signal of one or "n" frames before based on said motion vector;
• the second predictive residue is calculated by obtaining the differential between the motion compensation predicted video signal and the current video signal to be predicted, as well as the first predictive residue is calculated by obtaining differential between the hierarchy predicted video signal and the first hierarchical video signal to be predicted;
• and
• the coded video signal is decoded, said coded video signal being coded and transmitted by a digital video signal coding apparatus which transmits the predictive residues based on the first or second predictive residues, said second hierarchical and/or said motion vector,
• said coded image signal coding apparatus comprising:
• hierarchy prediction means for predicting said first hierarchical video signal from said second hierarchical video signal transmitted;
• motion compensated prediction means for predicting the current video signal based on the motion vector transmitted from said video signal of one or "n" frames before;
• and
• means for forming decoded video signal by adding the corresponding predictive residue transmitted to the prediction result obtained by said hierarchy prediction means and/or the prediction result obtained by said motion compensated prediction means.

A coded video signal decoding method wherein:

• the second hierarchical video signal having lower resolution than the first hierarchical video signal is formed;
• the motion vector between the current video signal and the video signal of one or "n" frames before said current video signal is detected;
• the video signal which corresponds to the first hierarchy is hierarchy predicted from said second hierarchical video signal;
• the current video signal is motion compensation predicted based on said motion vector from the video signal of one or "n" frames before;
• the second predictive residue is calculated by obtaining the differential between the video signal which is motion compensation predicted and the video signal to be predicted, as well as the first predictive residue is calculated by obtaining the differential between the video signal hierarchy which is compensation predicted and the first hierarchical video signal to be predicted;
• and
• the coded video signal is decoded, said coded video signal being coded and transmitted by the digital video signal coding method which transmits the predictive residue based on said first and/or second predictive residues, said second hierarchical video signal and/or said motion vector,
• said coded video signal decoding apparatus comprising the steps of:
• predicting said first hierarchical video signal from the transmitted second hierarchical video signal;
• predicting the current video signal based on the motion vector transmitted from said video signal of one or "n" frames before;
• and
• forming decoded video signal by adding the corresponding predictive residue transmitted to the prediction result obtained at said hierarchical prediction step and/or the prediction result obtained at said motion compensated prediction step.

A recording medium storing coded data which image is coded, which stores at least the coded data of:

• predictive residue data which is obtained by combining a plurality of processing;
• and
• the second hierarchical image data having lower resolution than first hierarchical image data which is formed based on image data of first hierarchy and/or motion vector between the current video signal and the video signal of one or "n" frames before said current video signal;
• wherein
• said predictive residue data comprising:
• first step of predicting said first hierarchical image data from said second hierarchical image data, and calculating first predictive residue by obtaining the differential between said hierarchical predicted video signal and first hierarchical video signal to be predicted;
• and
• second step of predicting said current video signal from said video signal of one or "n" frames before based on said motion vector, and calculating second predictive residue by obtaining the differential between said motion compensation predicted video signal and said current video signal to be predicted.