Method of adaptive intra prediction mode encoding and apparatus for the same, and method of encoding and apparatus for the same

An apparatus for encoding an intra prediction mode of an image, the apparatus comprising:

• a similarity detector to detect a similarity of a prediction direction of a neighbor block with respect to a current block based on a position of the neighbor block and an intra prediction direction of the neighbor block with respect to the current block;
• and
• a candidate prediction mode determining unit to determine a candidate prediction mode of the current block based on the similarity and the number of candidate intra prediction modes (N).

A method for decoding an intra prediction mode of an image, the method comprising:

• detecting a similarity of a prediction direction of a neighbor block with respect to a current block based on a position of the neighbor block and an intra prediction direction of the neighbor block with respect to the current block;
• and
• determining a candidate prediction mode of the current block based on the similarity and the number of candidate intra prediction modes (N).

An apparatus for decoding an intra prediction mode of an image, the apparatus comprising:

• a similarity detector to detect a similarity of a prediction direction of a neighbor block with respect to a current block based on a position of the neighbor block and an intra prediction direction of the neighbor block with respect to the current block;
• and
• a candidate prediction mode determining unit to determine a candidate prediction mode of the current block based on the similarity and the number of candidate intra prediction modes (N).