Alternatively, a decoding device may generate one list by combining a candidate mode list and a first group of the non-MPM. The generated list may be configured with intra prediction modes including the MPM and the second candidate group and may be rearranged in an ascending order. A rearranged intra prediction mode may be compared with remaining mode information. As a result of the comparison, when remaining mode information is greater than or equal to a rearranged intra prediction mode, a process which adds 1 to remaining mode information may be performed. The process may be sequentially performed for each of rearranged intra prediction modes. A decoding device may set a mode value obtained through the process as an intra prediction mode of a current block.
Illustrative methods of the present disclosure are represented as motion series for clarity of description, but it is not to limit an order that a stage is performed and if necessary, each stage may be performed simultaneously or in a different order. To implement a method according to the present disclosure, other stage may be additionally included in an illustrative stage, or remaining stages may be included except for some stages, or an additional other stage may be included except for some stages.
A variety of embodiments of the present disclosure do not enumerate all possible combinations, but are to describe the representative aspect of the present disclosure and matters described in various embodiments may be independently applied or may be applied by two or more combinations.