Intra prediction method and apparatus

An intra prediction method comprising:

• determining at least one sub-block on which intra prediction is to be performed, on the basis of intra prediction processing operation information of a macro block;
• detecting an intra prediction sample by performing the intra prediction of the determined at least one sub block;
• generating a reformed pixel value as a pixel value of a reference sub-block for a next intra prediction processing operation, when a pixel value of the determined at least one sub-block is reformed by adding a residual value of the determined at least one sub-block to the detected intra prediction sample;
• and
• updating the intra prediction processing operation information when the pixel value of the reference sub-block is generated.

An intra prediction apparatus usable when image encoding is performed, comprising:

• an intra prediction processing unit which determines at least one sub-block on which intra prediction is to be performed, on the basis of intra prediction processing operation information of a macro block, performs the intra prediction of the determined at least one sub-block on which intra prediction is to be performed, and outputs an intra prediction mode and intra prediction sample;
• an adder which adds a residual value of the determined at least one sub-block to the intra prediction sample;
• a reference pixel generator which reforms a pixel value of the determined at least one sub-block using a signal output from the adder and generates the reformed pixel value as a pixel value of a reference sub-block for a next intra prediction processing operation;
• and
• an intra prediction processing operation information provider which, when the pixel value of the reference sub-block is generated by the reference pixel generator, updates the intra prediction processing operation information.

An intra prediction apparatus usable when image decoding is performed, comprising:

• an intra prediction processing unit which determines at least one sub-block, on which intra prediction is to be performed, on the basis of intra prediction processing operation information of a macro block, performs intra prediction of the determined at least one sub-block on which intra prediction is to be performed, and outputs at least one corresponding intra prediction sample;
• an adder which adds a residual value of the determined at least one sub-block to the intra prediction sample;
• a reference pixel generator which reforms a pixel value of the determined at least one sub-block using a signal output from the adder and generates the reformed pixel value as a pixel value of a reference sub-block for a next intra prediction processing operation;
• and
• an intra prediction processing operation information provider which, when the pixel value of the reference sub-block is generated by the reference pixel generator, updates the intra prediction processing operation information.

A method of increasing intra prediction speed, comprising:

• determining, on the basis of intra prediction processing operation information of a macro block, a sub-block on which intra prediction is to be performed;
• performing intra prediction of the determined sub-block using at least one intra prediction mode so as to detect intra prediction samples thereof;
• calculating sum absolute errors (SAE) for each of the at least one intra prediction modes using each of the detected intra prediction samples and a current pixel value of a corresponding sub-block;
• detecting a minimum SAE value from among the SAE values;
• adding an intra prediction sample which has the minimum SAE value and a corresponding residual value;
• reforming a pixel value of the determined sub-block using the added value;
• generating a pixel value of a reference sub-block for a next intra prediction processing operation using the reformed pixel value;
• and
• updating the intra prediction processing operation information of the macro block.

An intra prediction method, comprising:

• determining, on the basis of intra prediction processing operation information on a macro block, at least one sub-block on which intra prediction is to be performed;
• performing intra prediction on the determined at least one sub-block to yield an intra prediction sample;
• reforming a pixel value of the determined at least one sub-block by adding a residual value of the determined at least one sub-block to the intra prediction sample, generating a reformed pixel value as a pixel value of a reference sub-block for a next intra prediction processing operation;
• and
• updating the intra prediction processing operation information on the pixel value of the reference sub-block using the reformed pixel value.