Moving image encoding apparatus and moving image encoding method

A moving image encoding method comprising:

• calculating encoding costs regarding each of a plurality of blocks having different block sizes on the basis of differences between original images of the plurality of blocks and specific prediction images of the plurality of blocks respectively wherein the plurality of blocks is defined by recursively dividing an encoding target image included in a moving image in each of a plurality of hierarchies;
• selecting a first block size in a first hierarchy among the plurality of hierarchies by comparing the encoding costs with each other,
• selecting a first intra-prediction mode for a first block having the first block size in the first hierarchy, and
• encoding the first block on the basis of a difference between a first prediction image of the first block generated by the first intra-prediction mode and a first original image of the first block.

A non-transitory computer-readable medium storing a moving image encoding program executable by a computer, the program comprising:

• instructions for calculating encoding costs regarding each of a plurality of blocks having different block sizes on the basis of differences between original images of the plurality of blocks and specific prediction images of the plurality of blocks respectively wherein the plurality of blocks is defined by recursively dividing an encoding target image included in a moving image in each of a plurality of hierarchies;
• instructions for selecting a first block size in a first hierarchy among the plurality of hierarchies by comparing the encoding costs with each other,
• instructions for selecting a first intra-prediction mode for a first block having the first block size in the first hierarchy, and
• instructions for encoding the first block on the basis of a difference between a first prediction image of the first block generated by the first intra-prediction mode and a first original image of the first block.