Video encoding/decoding method and apparatus, and recording medium in which bit stream is stored

An image encoding method comprising:

• determining an intra prediction mode of a current block;
• encoding a predetermined mode sameness indicator indicating whether or not the intra prediction mode of the current block is a predetermined mode based on the intra prediction mode of the current block
• deriving a reference sample of intra prediction of the current block;
• generating a prediction block of the current block by performing intra prediction of the current block based on the intra prediction mode and the reference sample;
• generating a residual block of the current block based on the prediction block of the current block;
• and
• generating the residual data of the current block by encoding the residual block,
• wherein in case the intra prediction mode of the current block is the predetermined mode, the predetermined mode sameness indicator is configured to indicate that the intra prediction mode of the current block is the predetermined mode, and
• in case the intra prediction mode of the current block is not the predetermined mode, the predetermined mode sameness indicator is configured to indicate that the intra prediction mode of the current block is determined from among a plurality of intra prediction modes that do not contain the predetermined mode.

A non-transitory computer readable recording medium storing a bitstream which is received, decoded and used to reconstruct an image by an image decoding apparatus,

• wherein the bitstream comprises a predetermined mode sameness indicator of a current block indicating whether or not an intra prediction mode of the current block is a predetermined mode and residual data of the current block,
• in case the predetermined mode sameness indicator indicating that the intra prediction mode of the current block is the predetermined mode, the intra prediction mode of the current block is determined to be the predetermined mode,
• in case the predetermined mode sameness indicator indicating that the intra prediction mode of the current block is not the predetermined mode, the intra prediction mode of the current block is determined from among a plurality of intra prediction modes that do not contain the predetermined mode,
• the intra prediction mode is used with a reference sample of the intra prediction to generate a prediction block of the current block by performing intra prediction of the current block,
• a residual block of the current block is generated based on the residual data of the current block, and
• the prediction block is used with a residual block to reconstruct the current block.