Method and device for encoding/decoding motion vector
A motion vector encoding apparatus includes: a predictor configured to obtain motion vector predictor candidates of a plurality of predetermined motion vector resolutions by using a spatial candidate block and a temporal candidate block of a current block, and to determine motion vector predictor of the current block, a motion vector of the current block, and a motion vector resolution of the current block by using the motion vector predictor candidates; and an encoder configured to encode information representing the motion vector predictor of the current block, a residual motion vector between the motion vector of the current block and the motion vector predictor of the current block, and information representing the motion vector resolution of the current block, wherein the plurality of predetermined motion vector resolutions include a resolution of a pixel unit that is greater than a resolution of one-pel unit.
1. A motion vector encoding apparatus comprising:
a predictor configured to obtain motion vector predictor by using at least one spatial block adjacent to a current block, and to determine a motion vector of the current block, and a motion vector resolution of the current block; and
an encoder configured to encode a residual motion vector between the motion vector of the current block and the motion vector predictor of the current block, and information representing the motion vector resolution of the current block,
wherein the encoder down-scales the residual motion vector when the motion vector resolution of the current block is not the same as a predetermined first motion vector resolution to encode the residual motion vector, and
wherein the encoder does not down-scale the residual motion vector when the motion vector resolution of the current block is the same as the predetermined first motion vector resolution to encode the residual motion vector.
2. The motion vector encoding apparatus of claim 1 , wherein the predictor determines the motion vector resolution of the current block among plurality of predetermined motion vector resolutions comprising the first motion vector resolution.
3. The motion vector encoding apparatus of claim 1 , wherein the predictor obtains the motion vector predictor by using a first spatial block when the motion vector resolution of the current block is the same a predetermined second motion vector resolution, and obtains the motion vector predictor by using a second spatial block when the motion vector resolution of the current block is the same a predetermined third motion vector resolution,
wherein locations of the first spatial block and the second spatial block are different each other.
4. A motion vector decoding apparatus comprising:
an obtainer configured to obtain motion vector predictor by using at least one spatial block adjacent to a current block, and to obtain a residual motion vector between a motion vector of the current block and the motion vector predictor of the current block, and information representing a motion vector resolution of the current block; and
a decoder configured to reconstruct the motion vector of the current block based on the residual motion vector, the motion vector predictor of the current block, and the information representing the motion vector resolution of the current block,
wherein the decoder up-scales the residual motion vector when the motion vector resolution of the current block is not the same as a predetermined first motion vector resolution to reconstruct the motion vector,
wherein the decoder does not up-scale the residual motion vector when the motion vector resolution of the current block is the same as the predetermined first motion vector resolution to reconstruct the motion vector.
5. The motion vector decoding apparatus of claim 4 , wherein the obtainer obtains the motion vector predictor by using a first spatial block when the motion vector resolution of the current block is the same a predetermined second motion vector resolution, and obtains the motion vector predictor by using a second spatial block when the motion vector resolution of the current block is the same a predetermined third motion vector resolution,
wherein locations of the first spatial block and the second spatial block are different each other.
6. A method for decoding a motion vector, the method comprising:
obtaining motion vector predictor by using at least one spatial block adjacent to a current block;
obtaining a residual motion vector between a motion vector of the current block and the motion vector predictor of the current block, and information representing a motion vector resolution of the current block; and
reconstructing the motion vector of the current block based on the residual motion vector, the motion vector predictor of the current block, and the information representing the motion vector resolution of the current block,
wherein the residual motion vector is up-scaled when the motion vector resolution of the current block is not the same as a predetermined first motion vector resolution to reconstruct the motion vector,
wherein the residual motion vector is not up-scaled when the motion vector resolution of the current block is the same as the predetermined first motion vector resolution to reconstruct the motion vector.
7. A non-transitory computer-readable recording medium having recorded thereon a program for performing the method of claim 6 .