Management and selection of reference frames for long term prediction in motion estimation
AssigneeVBrick Systems, Inc.
InventorsSassan Pejhan, Andrew Krupiczka
Life of this patent
Estimating the term…
Abstract
Reference frames are selected for use in a frame reference buffer in a video encoding system, so as to provide long term prediction of motion in video sequences. Candidate reference frames are characterized by characteristic vectors. From the candidate reference frames, a number of reference frames are maintained in the frame buffer so as to obtain a specified distribution of the characteristic vectors over a vector space. Frames are selected for use in encoding a current frame based on the characteristic vector of the current frame and the reference frames in the frame buffer.
Claims18
A method for selecting a reference frame in a frame buffer for encoding a current frame in a video encoding system, the method comprising:
- storing in a frame buffer a plurality of reference frames, each reference frame associated with a characteristic metric vector, the characteristic metric vector representing the reference frame in a frequency domain;
- generating for the current frame a characteristic metric vector representing the current frame in a frequency domain;
- determining an interframe distance between the current frame and at least one of the reference frames, the interframe distance based upon a distance between the characteristic metric vector of the current frame the characteristic metric vector of the reference frame;
- and
- selecting for encoding the current frame at least one reference frame for which the interframe distance is below a threshold distance.
A method for selecting reference frames for encoding a current frame in a video encoding system, wherein the current frame includes a plurality of blocks, the method comprising:
- storing in a frame buffer a plurality of reference frames, each reference frame comprising a plurality of blocks, each block associated with a characteristic metric vector, the characteristic metric vector representing the block of the reference frame in a frequency domain;
- generating for each block of the current frame a characteristic metric vector representing the block of the current frame in the frequency domain;
- for each block of the current frame being a current block:
- determining an interblock distance between the block of the current frame and each of those corresponding blocks in the plurality of reference frames, the interblock distance based upon a distance between the characteristic vector of the current block and each of those corresponding blocks in the plurality of reference frames;
- and
- selecting for encoding the current block those corresponding blocks in the plurality of reference frames for which the interblock distance is below a threshold distance.
An apparatus for selecting a reference frame in a frame buffer for encoding a current frame in a video encoding system, the apparatus comprising:
- a frame buffer for storing a plurality of reference frames, each reference frame associated with a characteristic metric vector, the characteristic metric vector representing the reference frame in a frequency domain;
- means for generating for the current frame a characteristic metric vector representing the current frame in the frequency domain;
- means for determining an interframe distance between the current frame and each reference frame, the interframe distance based upon a distance between the characteristic metric vector of the current frame the characteristic metric vector of the reference frame;
- means for selecting for encoding the current frame at least one reference frame for which the interframe distance is below a threshold distance.
An apparatus for selecting reference frames for encoding a current frame in a video encoding system, wherein the current frame includes a plurality of blocks, the apparatus comprising:
- a frame buffer for storing a plurality of reference frames, each reference frame comprising a plurality of blocks, each block associated with a characteristic metric vector, the characteristic metric vector representing the block of the reference frame in a frequency domain;
- means for generating for each block of the current frame a characteristic metric vector representing the block of the current frame in the frequency domain;
- and
- means for each block of the current frame:
- determining an interblock distance between the block of the current frame and each of those corresponding blocks in the plurality of reference frames, the interblock distance based upon a distance between the characteristic vector of the current block and each of those corresponding blocks in the plurality of reference frames;
- and
- selecting for encoding the current block of the current frame those corresponding blocks in the plurality of reference frames for which the interblock distance is below a threshold distance.
Dependencies are inferred from the claim text.