Intra prediction mode, and entropy encoding/decoding method and device

A video encoding method, comprising:

• determining an intra prediction mode of a current block;
• and
• deriving a prediction block for the current block by performing intra prediction for the current block based on the intra prediction mode of the current block,
• wherein a pixel value of a target pixel is generated by the intra prediction,
• wherein a filtered target pixel is generated by applying filtering to the target pixel of the prediction block,
• wherein the filtering is performed based on a sum of a first calculated value, a second calculated value and a third calculated value,
• wherein the filtered target pixel is a result of applying an arithmetic right shift by 6 bits to a sum of the first calculated value, the second calculated value, the third calculated value and a first constant,
• wherein the first calculated value is derived based on the pixel value of the target pixel,
• wherein the second calculated value is derived based on the pixel value of the target pixel, and
• wherein the third calculated value is derived based on the pixel value of the target pixel.

A method for sending a bitstream, wherein the bitstream is generated by a processor of an image encoding device, wherein the method comprises:

• sending the bitstream,
• wherein the bitstream comprises prediction mode information,
• wherein the prediction mode information indicates an intra prediction mode of a current block, and
• wherein the intra prediction mode of the current block is used to derive a prediction block for the current block by performing intra prediction for the current block,
• wherein a filtered target pixel is generated by applying filtering to a target pixel of the prediction block,
• wherein the filtering is performed based on a sum of a first calculated value, a second calculated value and a third calculated value,
• wherein the filtered target pixel is a result of applying an arithmetic right shift by 6 bits to a sum of the first calculated value, the second calculated value, the third calculated value and a first constant,
• wherein the first calculated value is derived based on a pixel value of the target pixel,
• wherein the second calculated value is derived based on a pixel value of the target pixel, and
• wherein the third calculated value is derived based on the pixel value of the target pixel.