Video encoding and decoding method

1. A method for decoding an image based on an intra prediction, comprising:

obtaining a first prediction pixel of a first region in a current block by using a neighboring pixel adjacent to the current block;

obtaining a second prediction pixel of a second region in the current block by using the first prediction pixel of the first region; and

decoding the current block based on the first and the second prediction pixels,

wherein the first region is composed of a plurality of pixels including a bottom-right pixel, a bottom pixel belonging to same bottom row as the bottom-right pixel, and a rightmost pixel belonging to same rightmost column as the bottom-right pixel, and

wherein the plurality of pixels in the first region is predicted by using the neighboring pixel adjacent to the current block without using other pre-obtained prediction pixels in the first region.

2. The method of claim 1 , wherein the first region in the current block includes a pixel belonging to at least one of a bottommost row in the current block or a rightmost column in the current block, and

wherein the second region in the current block is a region other than the first region in the current block.

3. The method of claim 2 , wherein the second prediction pixel of the second region in the current block is obtained by further using a neighboring pixel located on same vertical line as the second prediction pixel among neighboring pixels adjacent to a top of the current block.

4. The method of claim 2 , wherein the intra prediction is first performed on a pixel located at a position other than a top-left pixel of the current block.

5. The method of claim 4 , wherein a bottom-right pixel of the current block is predicted before the top-left pixel of the current block.

6. The method of claim 4 , wherein an intra prediction for the second region in the current block is performed after an intra prediction for the first region in the current block is completed.

7. A method for encoding an image based on an intra prediction, comprising:

obtaining a first prediction pixel of a first region in a current block by using a neighboring pixel adjacent to the current block;

obtaining a second prediction pixel of a second region in the current block by using the first prediction pixel of the first region; and

encoding the current block based on the first and the second prediction pixels,

wherein the first region is composed of a plurality of pixels including a bottom-right pixel, a bottom pixel belonging to same bottom row as the bottom-right pixel, and a rightmost pixel belonging to same rightmost column as the bottom-right pixel, and

wherein the plurality of pixels in the first region is predicted by using the neighboring pixel adjacent to the current block without using other pre-obtained prediction pixels in the first region.

8. A device of decoding a data stream associated with video data,

wherein the data stream comprising a current block encoded by an intra prediction,

wherein the current block is decoded based on a first prediction pixel of a first region in the current block and a second prediction pixel of a second region in the current block,

wherein the first prediction pixel of the first region in the current block is obtained by using a neighboring pixel adjacent to the current block,

wherein the second prediction pixel of the second region in the current block is obtained by using the first prediction pixel of the first region,

wherein the first region is composed of a plurality of pixels including a bottom-right pixel, a bottom pixel belonging to same bottom row as the bottom-right pixel, and a rightmost pixel belonging to same rightmost column as the bottom-right pixel, and

wherein the plurality of pixels in the first region is predicted by using the neighboring pixel adjacent to the current block without using other pre-obtained prediction pixels in the first region.