Patent ID: 8290064

Claim:
An intra-forecast mode selecting method of selecting an intra-forecast mode suitable for intra-forecast coding of a block to be encoded from a plurality of intra-forecast modes including a DC intra-forecast mode based on a coding amount of an intra-forecast mode and a forecast difference in intra-forecast, wherein it is decided whether an intra-forecast mode forecasted from an intra-forecast mode of an already-encoded block adjacent to the current block is an intra-forecast mode predetermined to be selected with higher priority than the DC intra-forecast mode, and only in a case that said forecasted intra-forecast mode is decided to be the intra-forecast mode predetermined to be selected with higher priority than the DC intra-forecast mode, a header coding amount of the DC intra-forecast mode is corrected to be no greater than those of other intra-forecast modes, and an intra-forecast mode is selected based on said corrected header coding amount of the DC intra-forecast mode, the header coding amounts of other intra-forecast modes and the forecast difference in intra-forecast.