Device and method for moving image encoding

A moving image encoding method, comprising:

• obtaining a region motion vector, by a computer processor, that represents a motion of a region including a block in a first slice, in a case where an encoding object block is included in a block line in a second slice, the block line contacting with a boundary between the first slice and the second slice in an encoding object picture, the encoding object picture being divided into a plurality of slices each of which includes a plurality of blocks;
• obtaining a motion vector of the encoding object block by using the region motion vector as a first prediction vector of the encoding object block;
• obtaining a second prediction vector from a motion vector of one or more encoded blocks that is or are positioned around the encoding object block;
• and
• obtaining an encoding result by encoding a difference vector between the motion vector of the encoding object block and the second prediction vector and encoding a difference between a pixel value of the encoding object block and a pixel value of a block in a reference picture that is represented by the motion vector of the encoding object block.

A non-transitory computer-readable storage medium storing an image processing program that causes a computer to execute a process comprising:

• obtaining a region motion vector that represents a motion of a region including a block in a first slice, in a case where an encoding object block is included in a block line in a second slice, the block line contacting with a boundary between the first slice and the second slice in an encoding object picture, the encoding object picture being divided into a plurality of slices each of which includes a plurality of blocks;
• obtaining a motion vector of the encoding object block by using the region motion vector as a first prediction vector of the encoding object block;
• obtaining a second prediction vector from a motion vector of one or more encoded blocks that is or are positioned around the encoding object block;
• and
• obtaining an encoding result by encoding a difference vector between the motion vector of the encoding object block and the second prediction vector and encoding a difference between a pixel value of the encoding object block and a pixel value of a block in a reference picture that is represented by the motion vector of the encoding object block.