US 6,584,155 B2Granted

Method and system for estimating motion vector

AssigneeKabushiki Kaisha Toshiba

InventorsHideki Takeda, Kunihiko Yahagi

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Abstract

The correlation between a coded block on the screen of the current image and a plurality of candidate blocks which exist in a search area on a reference screen temporally different from the current image and which has the same area as that of the coded block is obtained to select a candidate block having the highest correlation to obtain its displacement as a primary motion vector. Then, the positional relationship between a motion vector/corresponding candidate block and the reference screen is estimated to determine whether the search area/candidate block is positioned inside of the boundary of the reference screen. When a part of the search area/candidate block is positioned outside of the boundary, the position of the primary motion vector so that the search area/candidate block is located inside of the boundary of the reference. Thereafter, a secondary motion vector is estimated using the corrected motion vector and the correction quantity to obtain a desired motion vector on the basis of the primary motion vector, the correction quantity and the secondary motion vector. Thus, the correction quantity is added during the motion vector estimation for the edge of the reference screen, to put the search area in the reference screen during the estimation of a desired motion vector, so as to improve the estimation precision.

Claims18

Dependent claims

A method for estimating a motion vector of a dynamic image, said method comprising the steps of:

obtaining the correlation between a coded block occupying an optional area on a screen of a coded current image, and a plurality of candidate blocks which exist in a search area having an optional size on a screen of a reference image temporally different from the current image and which occupies the same area as that of the coded block;
selecting a candidate block having the highest correlation from said plurality of candidate blocks to obtain a displacement at that time as a primary motion vector;
determining a secondary search area on the basis of said primary motion vector to estimate a positional relationship between a plurality of secondary candidate blocks, which occupy the same area as that of said coded block existing in the determined secondary search area, or said primary motion vector and said reference screen to determine whether said secondary search area or said secondary candidate block is positioned outside of the boundary of said reference screen;
correcting the position of said primary motion vector by a correction quantity obtained in the manner that said secondary search area or said secondary candidate block is located inside of the boundary of said reference screen, when it is determined that a part of said secondary search area or secondary candidate block is positioned outside of said boundary;
obtaining the correlation between the plurality of corrected secondary candidate blocks, which exist in the corrected secondary search area based on the motion vector, the position of which has been corrected, and which occupy the same area as that of said coded block, and said coded block;
selecting a secondary candidate block having the highest correlation from said plurality of secondary candidate blocks to obtain a displacement at that time as a secondary motion vector;
and
obtaining a desired motion vector on the basis of said primary motion vector, said correction quantity and said secondary motion vector.

5 more elements

A method for estimating a motion vector of a dynamic image, by obtaining a desired motion vector by using one through n (n is a positive and integer number) motion vector (vectors) and respective moving quantity between respective motion vectors, said method comprising:

a step of obtaining the correlation between a coded block occupying an optional area on a screen of a coded current image, and a plurality of candidate blocks which exist in an (i−1)-th search area (1<i<=n) having an optional size on a screen of a reference image temporally different from the current image and which occupies the same area as that of the coded block;
a step of selecting a candidate block having the highest correlation from said plurality of candidate blocks to obtain a displacement at that time as an (i−1)-th motion vector;
a step of determining an i-th search area on the basis of said (i−1)-th motion vector to estimate a positional relationship between a plurality of i-th candidate blocks, which occupy the same area as that of said coded block existing in the determined i-th search area, or said (i−1)-th motion vector and said reference screen to determine whether said i-th search area or said i-th candidate block is positioned outside of the boundary of said reference screen;
a step of correcting the position of said (i−1)-th motion vector by an (i−1) -th correction quantity obtained in the manner that said i-th search area or said i-th candidate block is located inside of the boundary of said reference screen, when it is determined that a part of said i-th search area or i-th candidate block is positioned outside of said boundary;
a step of obtaining the correlation between the plurality of corrected i-th candidate blocks, which exist in the corrected i-th search area based on the motion vector, the position of which has been corrected, and which occupy the same area as that of said coded block, and said coded block;
and
a step of selecting a secondary candidate block having the highest correlation from said plurality of i-th candidate blocks to obtain a displacement at that time as an i-th motion vector;
and wherein said method further comprising:
a step of obtaining a desired motion vector on the basis of said primary motion vector, primary correction quantity, . . . , (n−1)-th motion vector, (n−1)-th correction quantity, and n-th motion vector.

6 more elements

A system for estimating a motion vector of a dynamic image, said system comprising:

a primary motion vector estimating part for obtaining the correlation between a coded block occupying an optional area on a screen of a coded current image, and a plurality of candidate blocks which exist in a search area having an optional size on a screen of a reference image temporally different from the current image and which occupies the same area as that of the coded block, to select a candidate block having the highest correlation from said plurality of candidate blocks to obtain a displacement at that time as a primary motion vector;
a primary motion vector position determining part for determining a secondary search area on the basis of said primary motion vector to estimate a positional relationship between a plurality of secondary candidate blocks, which occupy the same area as that of said coded block existing in the determined secondary search area, or said primary motion vector and said reference screen to determine whether said secondary search area or said secondary candidate block is positioned outside of the boundary of said reference screen;
a primary motion vector position correcting part for correcting the position of said primary motion vector by a correction quantity obtained in the manner that said secondary search area or said secondary candidate block is located inside of the boundary of said reference screen, when it is determined that a part of said secondary search area or secondary candidate block is positioned outside of said boundary;
a secondary motion vector estimating part for obtaining the correlation between the plurality of corrected secondary candidate blocks, which exist in the corrected secondary search area based on the motion vector, the position of which has been corrected, and which occupy the same area as that of said coded block, and said coded block, to select a secondary candidate block having the highest correlation from said plurality of secondary candidate blocks to obtain a displacement at that time as a secondary motion vector;
and
a desired motion vector estimating part for obtaining a desired motion vector on the basis of said primary motion vector, said correction quantity and said secondary motion vector.

3 more elements

A system for estimating a motion vector of a dynamic image, by obtaining a desired motion vector by using one through n (n is a positive and integer number) motion vector (vectors) and respective moving quantity between respective motion vectors, said system comprising:

an (i−1)-th motion vector estimating part for obtaining the correlation between a coded block occupying an optional area on a screen of a coded current image, and a plurality of candidate blocks which exist in an (i−1)-th search area (1<i<=n) having an optional size on a screen of a reference image temporally different from the current image and which occupies the same area as that of the coded block, to select a candidate block having the highest correlation from said plurality of candidate blocks to obtain a displacement at that time as an (i−1) -th motion vector;
an (i−1)-th motion vector position determining part for determining an i-th search area on the basis of said (i−1)-th motion vector to estimate a positional relationship between a plurality of i-th candidate blocks, which occupy the same area as that of said coded block existing in the determined i-th search area, or said (i−1)-th motion vector and said reference screen to determine whether said i-th search area or said i-th candidate block is positioned outside of the boundary of said reference screen;
an (i−1)-th motion vector position correcting part for correcting the position of said (i−1)-th motion vector by a correction quantity obtained in the manner that said i-th search area or said i-th candidate block is located inside of the boundary of said reference screen, when it is determined that a part of said i-th search area or i-th candidate block is positioned outside of said boundary;
an i-th motion vector estimating part for obtaining the correlation between the plurality of corrected i-th candidate blocks, which exist in the corrected i-th search area based on the motion vector, the position of which has been corrected, and which occupy the same area as that of said coded block, and said coded block, to select an i-th candidate block having the highest correlation from said plurality of i-th candidate blocks to obtain a displacement at that time as an i-th motion vector;
and
a desired motion vector estimating part for obtaining a desired motion vector on the basis of said (i−1)-th motion vector, said correction quantity and said i-th motion vector.

3 more elements

A computer program including motion vector estimating procedures which comprise:

a procedure for obtaining the correlation between a coded block occupying an optional area on a screen of a coded current image, and a plurality of candidate blocks which exist in a search area having an optional size on a screen of a reference image temporally different from the current image and which occupies the same area as that of said coded block;
a procedure for selecting a candidate block having the highest correlation from said plurality of candidate blocks to obtain a displacement at that time as a primary motion vector;
a procedure for determining a secondary search area on the basis of said primary motion vector to estimate a positional relationship between a plurality of candidate blocks, which occupy the same area as that of said coded block existing in the determined secondary search area, or said primary motion vector and said reference screen to determine whether said secondary search area or said secondary candidate block is positioned outside of the boundary of said reference screen;
a procedure for correcting the position of said primary motion vector by a correction quantity obtained in the manner that said secondary search area or said secondary candidate block is located inside of the boundary of said reference screen, when it is determined that a part of said secondary search area or secondary candidate block is positioned outside of said boundary;
a procedure for obtaining the correlation between said plurality of corrected secondary candidate blocks, which exist in said corrected secondary search area based on the motion vector, the position of which has been corrected, and which occupy the same area as that of said coded block, and said coded block;
a procedure for selecting a secondary candidate block having the highest correlation from said plurality of secondary candidate blocks to obtain a displacement at that time as a secondary motion vector;
and
a procedure for obtaining a desired motion vector on the basis of said primary motion vector, said correction quantity and said secondary motion vector.

5 more elements

A computer program including motion vector estimating procedure, for obtaining a desired motion vector by using one through n (n is a positive and integer number) motion vector (vectors) and respective moving quantity between respective motion vectors, said computer program comprising:

a procedure for obtaining the correlation between a coded block occupying an optional area on a screen of a coded current image, and a plurality of candidate blocks which exist in an (i−1)-th search area (1<i<=n) having an optional size on a screen of a reference image temporally different from the current image and which occupies the same area as that of said coded block;
a procedure for selecting a candidate block having the highest correlation from said plurality of candidate blocks to obtain a displacement at that time as a primary motion vector;
a procedure for determining an i-th search area on the basis of said (i−1)-th motion vector to estimate a positional relationship between a plurality of i-th candidate blocks, which occupy the same area as that of said coded block existing in the determined i-th search area, or said (i−1)-th motion vector and said reference screen to determine whether said i-th search area or said i-th candidate block is positioned outside of the boundary of said reference screen;
a procedure for correcting the position of said (i−1)-th motion vector by a correction quantity obtained in the manner that said i-th search area or said i-th candidate block is located inside of the boundary of said reference screen, when it is determined that a part of said i-th search area or i-th candidate block is positioned outside of said boundary;
a procedure for obtaining the correlation between said plurality of corrected i-th candidate blocks, which exist in said corrected i-th search area based on the motion vector, the position of which has been corrected, and which occupy the same area as that of said coded block, and said coded block;
and
a procedure for selecting a i-th candidate block having the highest correlation from said plurality of i-th candidate blocks to obtain a displacement at that time as a i-th motion vector;
and wherein said computer program further comprising:
a procedure for obtaining a desired motion vector on the basis of a primary motion vector, a primary correction quantity, . . . , said (i−1)-th motion vector, said (i−1)-th correction quantity, said i-th motion vector, i-th correction quantity and n-th motion vector.

6 more elements

Dependencies are inferred from the claim text.

Facts

Application: 09/746,020Filed 26 Dec 2000
Priority: JP 11-36935327 Dec 1999
Published: US 2001/0008545 A119 Jul 2001
Granted: 24 Jun 2003
Term ends: Not estimatedThe source records don’t support an estimate.

Classification8 codes

H04N 5/145
Movement detection: movement estimation
G06T 7/238
Using block-matching: using non-full search, e.g. three-step search
H04N 19/533
Motion estimation or motion compensation: motion estimation using multistep search, e.g. two-dimensional [2D]-log search or one-at-a-time search [OTS]
H04N 19/56
Motion estimation or motion compensation: motion estimation with initialisation of the vector search, e.g. estimating a good candidate to initiate…