CODING METHOD USING MOTION MODEL INFORMATION

1 . An image coding method comprising:

obtaining motion model information indicating three-dimensional movement of a target object between a coding target picture and a reference picture;

deriving a prediction motion vector candidate from a prediction value of a motion vector of a coding target block included in the coding target picture, the prediction value of the motion vector derived using the motion model information; and

coding the coding target block using a prediction motion vector selected from a plurality of prediction motion vector candidates including the prediction motion vector candidate.

2 . The image coding method according to claim 1 ,

wherein in the obtaining, the motion model information is extracted from at least one image included in a plurality of images.

3 . The image coding method according to claim 1 , further comprising:

generating an object image by performing a deformation processing on a representative image of the target object based on the motion model information;

generating the reference picture by a combination of the object image and a background image, and

wherein in the coding, the coding target block is coded using the reference picture and the selected prediction motion vector.

4 . The image coding method according to claim 3 ,

wherein the motion model information is expressed as a plurality of coefficients of a high-order transform matrix, and

in the generating of the object image, the deformation processing includes performing a calculation on the representative image using the high-order transform matrix.

5 . The image coding method according to claim 4 , wherein the high-order transform matrix includes a coefficient that changes with time.

6 . The image coding method according to claim 1 , further comprising:

performing a motion searching processing on the coding target block using the prediction value as an initial value.

7 . The image coding method according to claim 1 , further comprising:

estimating the motion vector of the coding target block;

calculating the prediction motion vector candidate for the coding target block using the motion model information; and

coding a difference between one of a plurality of prediction motion vector candidates including the calculated prediction motion vector candidate and the estimated motion vector.

8 . An image decoding method comprising:

obtaining motion model information indicating three-dimensional movement of a target object between a decoding target picture and a reference picture;

deriving a prediction motion vector candidate from a prediction value of a motion vector of a coding target block included in the decoding target picture, the prediction value of the motion vector derived using the motion model information; and

decoding the decoding target block using a prediction motion vector selected from a plurality of prediction motion vector candidates including the prediction motion vector candidate.

9 . The image decoding method according to claim 8 ,

wherein in the obtaining, the motion model information is obtained from at least one image included in a plurality of images.

10 . The image coding method according to claim 8 , further comprising:

generating an object image by performing a deformation processing on a representative image of the target object based on the motion model information;

generating the reference picture by a combination of the object image and a background image, and

in the decoding, the decoding target block is decoded using the reference picture and the selected prediction motion vector.

11 . The image decoding method according to claim 8 ,

wherein the motion model information is expressed as a plurality of coefficients of a high-order transform matrix, and

in the generating of the object image, the deformation processing includes performing a calculation on the target image using the high-order transform matrix.

12 . The image decoding method according to claim 11 ,

wherein the high-order transform matrix includes a coefficient that changes with time.

13 . The image decoding method according to claim 8 , further comprising:

decoding a difference value of the motion vector of the decoding target block; and

calculating the motion vector by adding one of a plurality of prediction motion vector candidates including the calculated prediction motion vector candidate and the difference value to each other.

14 . An image coding apparatus that codes a plurality of images, the image coding apparatus comprising:

a processor; and

a memory storing thereon a computer program, which when executed by the processor, causes the processor to perform the image coding method according to claim 1 .

15 . An image decoding apparatus that decodes a plurality of images from a bit stream, the image decoding apparatus comprising:

a processor; and

a memory storing thereon a computer program, which when executed by the processor, causes the processor to perform the image coding method according to claim 8 .

16 . A content distribution method comprising:

receiving a content distribution request; and

transmitting a content subjected to the image coding method according to claim 1 based on the content distribution request.