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Using unitary transforms for MPEG block motion estimation Cavén, Ian Roger
Abstract
Block motion estimation, a stage of the MPEG video encoding process which significantly effects the quality and bit rate of an encoded video sequence, is also the most computation intensive part of the encoding process. To reduce the number of operations in this step, it is proposed that unitary transforms may be used to create condensed versions of the data, called block signatures, which can be used in place of the original video data during the matching process. Continuing previous work, this thesis studies several unitary transforms for their utility in creating signatures with the desired properties, with the focus being on how to select and allocate bits to the transform coefficients, and it considers the efficient computation of these signatures. Hardware and software implementations incorporating these signatures are suggested and discussed, and the results of implementing two proposed signature matching algorithms are described. A signature composed of sixty-four discrete cosine transform coefficients was found to work well in a full-search matching scheme appropriate for hardware implementation. The other proposed signature matching algorithm, which attempts to minimise the difference between the coefficients one at a time during the search for matches, performed poorly since the transform coefficients with most of the energy in the signal also tend contain most of the energy in the prediction error as well, and therefore the differences between these higher energy coefficients can not be minimised too early in the search process. Further work is needed to determine if a joint minimisation of differences between the transform coefficients of a target block and the set of available matches would be effective.
Item Metadata
Title |
Using unitary transforms for MPEG block motion estimation
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Creator | |
Publisher |
University of British Columbia
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Date Issued |
1998
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Description |
Block motion estimation, a stage of the MPEG video encoding process which
significantly effects the quality and bit rate of an encoded video sequence, is also the
most computation intensive part of the encoding process. To reduce the number of
operations in this step, it is proposed that unitary transforms may be used to create
condensed versions of the data, called block signatures, which can be used in place of
the original video data during the matching process. Continuing previous work, this
thesis studies several unitary transforms for their utility in creating signatures with the
desired properties, with the focus being on how to select and allocate bits to the
transform coefficients, and it considers the efficient computation of these signatures.
Hardware and software implementations incorporating these signatures are suggested
and discussed, and the results of implementing two proposed signature matching
algorithms are described. A signature composed of sixty-four discrete cosine transform
coefficients was found to work well in a full-search matching scheme appropriate for
hardware implementation. The other proposed signature matching algorithm, which
attempts to minimise the difference between the coefficients one at a time during the
search for matches, performed poorly since the transform coefficients with most of the
energy in the signal also tend contain most of the energy in the prediction error as well,
and therefore the differences between these higher energy coefficients can not be
minimised too early in the search process. Further work is needed to determine if a
joint minimisation of differences between the transform coefficients of a target block
and the set of available matches would be effective.
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Extent |
21534190 bytes
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Genre | |
Type | |
File Format |
application/pdf
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Language |
eng
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Date Available |
2009-05-22
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Provider |
Vancouver : University of British Columbia Library
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Rights |
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.
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DOI |
10.14288/1.0065082
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URI | |
Degree | |
Program | |
Affiliation | |
Degree Grantor |
University of British Columbia
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Graduation Date |
1998-11
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Campus | |
Scholarly Level |
Graduate
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Aggregated Source Repository |
DSpace
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Item Media
Item Citations and Data
Rights
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.