Motion estimator
AssigneeBritish Telecommunications public limited company
InventorIan Parke
Life of this patent
Estimating the term…
Abstract
A motion vector for motion-compensated prediction in an inter-frame differential video coder is derived by comparing each block in a row of a current frame with the corresponding region, and positionally shifted regions, of a previous frame. The blocks are processed row by row, and scanned in a vertical column-by-column scan with each of the shifted regions. Two or more rows may be processed at a time. For .+-.7 pixel search, two or four comparison processors are provided, one (or one pair) processing odd-numbered blocks and the other (or other pair) processing even-numbered blocks. For a .+-.15 pixel search, four or eight processors are provided. The vertical scan is provided using a serial FIFO store including eight 8 tap SIPO sections.
Claims15
A motion detector for video signals comprising:
- means for reception and temporary storage of signals representing one line-scanned frame of a picture and of signals representing another such frame of the picture;
- and
- means for comparing each of a plurality of blocks into which the said one frame is divided with the corresponding region of the other frame and with a plurality of positionally shifted regions of the other frame, to produce vector information indicating the positional shift if any between the position of the block and the position of that region of the other frame which meets a criterion of similarity between the block and the region;
- said comparison means including means arranged to operate sequentially upon blocks disposed in rows aligned with the picture line direction of said one frame, and to compare each with the said plurality of positionally shifted regions of the other frame in a sequential column-by-column scan of part of said other frame.
A motion detector for video signals comprising:
- means for reception and temporary storage of signals representing one line-scanned frame of a picture and of signals representing another such frame of the picture;
- and
- means for comparing each of a plurality of blocks into which the said one frame is divided with the corresponding region of the other frame and with a plurality of positionally shifted regions of the other frame, to produce vector information indicating the positional shift if any between the position of the block and the position of that region of the other frame which meets a criterion of similarity between the block and the region;
- said comparison means including means arranged to operate sequentially upon blocks disposed in columns aligned normal to the picture line direction of said one frame, and to compare each with the said plurality of positionally shifted regions of the other frame in a sequential row-by-row scan of part of said other frame.
A motion detector for digital video signals comprising:
- a first digital data store for storing at least a block of m columns of n rows of pixel values for a first frame of digital video signals;
- a second digital data store for storing at least a block of D-n+1 rows of m columns of pixel values for a second frame of digital video signals, D being the scan depth of motion searching to be performed along each column;
- said second digital data store including a FIFO register with m SIPO sections providing m.times.n pixel values corresponding to an m.times.n pixel window which provides m.times.n pixel values at successive scan positions, row-by-row along each of plural successive columns so as to effect a column-by-column motion detection search over the second frame digital video signals as pixel values therefore are serially shifted into said FIFO register;
- and
- arithmetic circuits connected to receive in parallel, said m.times.n pixel values from said first data store and said m.times.n pixel values from said SIPO sections of said second data store, and to compute a similarity value for each scan position of the second frame video signals in said second data store.
Dependencies are inferred from the claim text.