Method and apparatus for detecting motion
AssigneeHitachi, Ltd.
InventorsHiromi Watanabe, Kenichi Iwata, Hiroshi Hatae
Life of this patent
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Abstract
There is disclosed a method and apparatus for detecting motion by a video encoder. The method starts with dividing a target block whose motion is to be detected into blocks at different pixel positions. A reference image block is extracted from a reference image. The degrees of similarity of the blocks to the reference image block are simultaneously calculated by a calculating unit. A block having the highest degree of similarity is determined, based on their degrees of similarity. A vector corresponding to the determined block is taken as a motion vector representing the block.
Claims17
A method of dividing a frame of a target image whose motion is to be detected into plural target blocks and detecting motion vectors representing motions of said target blocks relative to a reference frame of image, said method comprising the steps of:
- dividing a target block into a plurality of blocks each of which has different pixel positions from each other wherein each of the plurality of blocks is allocated for one of vectors representing motions of said target block;
- comparing said plurality of blocks with a reference image block extracted from a search area within said reference frame of image, with respect to pixel data;
- finding degrees of similarity of said plurality of blocks to said reference image block;
- selecting one of said plurality of blocks according to the found degrees of similarity;
- and
- detecting a vector allocated to the selected block as a candidate of the motion vector representing motion of the target block.
An apparatus for detecting a motion vector representing motion of a target block which is one of plurality of target blocks being provided from a frame of a target image by dividing the frame of the target image, relative to a reference frame of image, comprising:
- a dividing unit dividing said target block into a plurality of blocks each of which has different pixel positions from each other, wherein each of the plurality of blocks is allocated to one of vectors representing motions of said target block;
- a parallel calculating unit comparing said plurality of blocks with a reference image block extracted from a search area within said reference frame of image, with respect to pixel data, and finding degrees of similarity of said plurality of blocks to said reference image block;
- and
- an approximate block detection unit selecting one of said plurality of blocks according to the found degrees of similarity and detecting a vector allocated to the selected block as a candidate of the motion vector representing motion of the target block.
An image encoder comprising;
- a detection unit detecting a motion vector representing motion of a target block which is one of plurarity of target blocks being provided from a frame of a target image by dividing the frame of the target image, relative to a reference frame of image, wherein the detection unit comprises;
- a dividing unit dividing said target block into a plurality of blocks each of which has different pixel positions from each other, wherein each of the plurality of blocks is allocated to one of vectors representing motions of said target block;
- a parallel calculating unit comparing said plurality of blocks with a reference image block extracted from a search area within said reference image frame, with respect to pixel data, and finding degrees of similarity of said plurality of blocks to said reference image block;
- an approximate block detection unit selecting one of said plurality of blocks according to the found degrees of similarity and detecting a vector allocated to the selected block as a candidate of the motion vector representing motion of the target block;
- an arithmetic unit providing differences in pixel between the reference image block represented by the motion vector detected by detection unit and the target block;
- a converter converting said differences;
- an encoding portion encoding the output signal from said converter and said motion vector;
- a decoding portion deriving said reference frame of image from the output signal from said converter;
- and
- a motion compensator receiving an output signal from said decoding portion and a target block from a block dividing unit and producing said motion vectors and said target block applied to said arithmetic unit.
A method of detecting motion, comprising the steps of:
- dividing a target block whose motion is to be detected into a plurality of blocks at different pixel positions;
- comparing each of the plurality of blocks with one reference image block extracted from a search area in a reference image;
- and
- selecting one from said plurality of blocks according to result of the comparison.
A motion-detecting apparatus comprising:
- a first memory storing a target block whose motion is to be detected and a reference image against which said target block is compared;
- a second memory connected with said first memory via a bus, said second memory being loaded with data about blocks obtained by dividing said target block by a data transfer operation via said bus, said blocks being composed of pixels and at different pixel positions;
- and
- a processing unit comparing said blocks with said reference image block and selecting one from of said blocks according to result of the comparison.
Dependencies are inferred from the claim text.