Video encoding and decoding method
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.
1. An image decoding method, which is performed by an image decoding apparatus, the method comprising:
dividing a current block into two regions including a first region and a second region, a current pixel belonging to the first region;
performing intra prediction on the first region of the current block; and
performing intra prediction on the second region of the current block based on the first region in which the intra prediction on the first region is completed,
wherein performing the intra prediction on the first region of the current block comprises:
obtaining a first neighboring pixel of the first region belonging to the same horizontal line as the current pixel belonging to the first region;
obtaining a second neighboring pixel of the first region belonging to the same vertical line as the current pixel belonging to the first region; and
generating a prediction value of the current pixel by applying weights to the first neighboring pixel and the second neighboring pixel, and
wherein the prediction value of the current pixel is generated by using a pixel T belonging to a block adjacent to an upper right corner of the first region and a pixel L belonging to a block adjacent to a lower left corner of the first region.
2. The method of claim 1 ,
wherein the weights include a first weight applied to a first reference pixel and a second weight applied to a second reference pixel.
3. The method of claim 2 ,
wherein the weights are determined based on at least one of a direction of the current block or a position of the current pixel.
4. The method of claim 3 ,
wherein in response to the direction of the current block being a horizontal direction, the first weight applied to the first reference pixel is smaller than the second weight applied to the second reference pixel.
5. An image encoding method, which is performed by an image encoding apparatus, the method comprising:
dividing a current block into two regions including a first region and a second region, a current pixel belonging to the first region;
performing intra prediction on the first region of the current block; and
performing intra prediction on the second region of the current block based on the first region in which the intra prediction on the first region is completed,
wherein performing the intra prediction on the first region of the current block comprises:
obtaining a first neighboring pixel of the first region belonging to the same horizontal line as the current pixel belonging to the first region;
obtaining a second neighboring pixel of the first region belonging to the same vertical line as the current pixel belonging to the first region; and
generating a prediction value of the current pixel by applying weights to the first neighboring pixel and the second neighboring pixel, and
wherein the prediction value of the current pixel is generated by using a pixel T belonging to a block adjacent to an upper right corner of the first region and a pixel L belonging to a block adjacent to a lower left corner of the first region.
6. The method of claim 5 ,
wherein the weights include a first weight applied to a first reference pixel and a second weight applied to a second reference pixel.
7. The method of claim 6 ,
wherein the weights are determined based on at least one of a direction of the current block or a position of the current pixel.
8. The method of claim 7 ,
wherein in response to the direction of the current block being a horizontal direction, the first weight applied to the first reference pixel is smaller than the second weight applied to the second reference pixel.
9. A non-transitory computer-readable medium storing a bitstream generated by an encoding method, the method comprising:
dividing a current block into two regions including a first region and a second region, a current pixel belonging to the first region;
performing intra prediction on the first region of the current block; and
performing intra prediction on the second region of the current block based on the first region in which the intra prediction on the first region is completed,
wherein, based on the intra prediction on the first region, prediction information is encoded into the bitstream,
wherein performing the intra prediction on the first region of the current block comprises:
obtaining a first neighboring pixel of the first region belonging to the same horizontal line as the current pixel belonging to the first region;
obtaining a second neighboring pixel of the first region belonging to the same vertical line as the current pixel belonging to the first region; and
generating a prediction value of the current pixel by applying weights to the first neighboring pixel and the second neighboring pixel, and
wherein the prediction value of the current pixel is generated by using a pixel T belonging to a block adjacent to an upper right corner of the first region and a pixel L belonging to a block adjacent to a lower left corner of the first region.