Patent EP0889652A2 successfully refreshed from Google Patents.
EP0889652A2
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Method and apparatus for encoding a contour of an object based on a contour motion estimation technique
Assignee: WiniaDaewoo Co Ltd
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Filing: 1997-09-05
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Granted: —
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Expires: 2017-09-05
Abstract
Abstract A contour encoding apparatus encoding a contour of an object in a current frame based on a previous frame first generates a global motion vector between the current and the previous frames and calculates the number of contours in the previous frame. Then, the apparatus determines, for each of current contours, an optimum contour among the previous contours and detects a local motion vector between the optimum and the current contours. Once the global and the local motion vectors are determined, a predicted contour corresponding to each of the current contours is generated by shifting the optimum contour by the global and the local motion vectors. By using the predicted and the current contours, an error representing a difference therebetween is extracted. Subsequently, flag signals describing how close each of the previous contours is to a corresponding current contour are produced based on the number of the previous contours and contour encoding information corresponding to each of the current contours and sequences of the errors and the local motion vectors for the current frame are outputted based on the contour encoding information corresponding to each of the current contours. Finally, the flag signals and the sequences of the errors and the local motion vectors are multiplexed and then the multiplexed data is transmitted as an encoded contour data.
Inventors
- 👤 Seok-Won Video Research Center Han
- 👤 Jin-Hun Video Research Center Kim
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 11:02
CPC Classifications
G; G06; G06T; G06T9/00; G06T9/20; H; H04; H04N; H04N19/00; H04N19/50; H04N19/503; H04N19/51; H04N19/527; H04N19/537; H04N19/54; H04N19/543
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
338 words
A method for encoding a contour of an object in a current
frame based on a previous frame, wherein the current and the
previous frames include one or more objects, respectively,
each of the objects having a contour, comprising the steps of: (a) generating a global motion vector representing a
displacement between the current and the previous frames which
yields a largest number of overlapping object pixels
therebetween; (b) detecting the contours of the objects in the previous
frame as previous contours, providing a contour number
representing the number of the previous contours, and
assigning index data to each of the previous contours in
response to a predetermined processing order; (c) choosing one of the contours in the current frame as
a current contour; (d) determining an optimum contour among the previous
contours and setting a displacement between the current
contour and the optimum contour as a local motion vector, the
optimum contour being a contour among the previous contours
most similar to the current contour; (e) producing a predicted contour by shifting the optimum
contour based on the global and the local motion vectors; (f) detecting an error representing a difference between
the predicted contour and the current contour; (g) repeating the steps of (c) to (f) until all of the
current contours in the current frame are processed; (h) generating flag signals describing how close each of
the previous contours is to a corresponding current contour
detected in the step (d) based on the contour number and
contour encoding information corresponding to each of the
current contours, wherein the contour encoding information
contains the index data of the optimum contour, the error, and
the local motion vector; (i) providing sequences of the errors and the local
motion vectors for the current frame based on the contour
encoding information corresponding to said each of the current
contours; and (j) outputting encoded contour data of the current frame
by encoding the global motion vector, the sequences of the
errors and the local motion vectors, and the flag signals.
Claim 2
Dependent Claim
268 words
The method according to claim 1, wherein the step (h)
includes the steps of: (h1) providing a Gfs_flag signal by comparing the number
of previous contours, which completely overlap with their
corresponding current contours through global motion
compensation, with a predetermined threshold value, wherein
the global motion compensation is performed by shifting one of
the current and the previous frames toward the other by the
global motion vector; (h2) generating, in response to the Gfs_flag signal, a
Global_flag signal containing L bits, each bit representing
whether or not its corresponding previous contour completely
overlaps with one of the current contours by the global motion
compensation, L being the contour number; (h3) supplying, in response to the Gfs_flag signal, a
Contour_flag signal having M bits, each bit showing whether or
not its corresponding previous contour completely or partially
overlaps with one of the current contours in a preset search
range by a global and local motion compensation, wherein the
global and local motion compensation is carried out based on
the global motion vector and the local motion vector
corresponding to each of the current contours, M being a
positive integer; and (h4) producing, in response to the Gfs_flag signal, the
Contour_flag_status signal containing N bits, each bit
illustrating whether or not its corresponding previous contour
completely overlaps with one of the current contours by the
global and local motion compensation, wherein the overlapping
degree of each of the previous contours and its corresponding
current contour is determined based on the contour number and
the contour encoding information corresponding to each of the
current contours, N being a positive integer.
Claim 3
Dependent Claim
29 words
The method according to claim 2, wherein each of the
sequences of the flag signals follows the sequence of the
index data assigned to each of the previous contours.
Claim 4
Dependent Claim
47 words
The method according to claim 3, wherein the Gfs_flag
signal has a logic value of: 1 if L < 4xGPM 0 if L %%ge%% 4xGPM wherein GPM is the number of the previous contours which
completely overlap with their corresponding current contours
through the global motion compensation.
Claim 5
Dependent Claim
29 words
The method according to claim 4, wherein if the Gfs_flag
signal has a logic value 1, the Global_flag signal is
generated and, if otherwise, the Global_flag signal is not.
Claim 6
Dependent Claim
39 words
The method according to claim 5, wherein the Global_flag
signal consists of L bits, each bit having a logic value 1
when its corresponding previous contour completely overlaps
with one of the current contours by the global motion
compensation.
Claim 7
Dependent Claim
156 words
The method according to claim 6, wherein the Contour_flag
signal includes two different bit streams as: if the Gfs_flag signal has a logic value 1, it is
represented by M bits, M being equal to L-GPM, wherein each
bit describes each of the rest of the previous contours except
those previous contours perfectly overlapping with one of the
current contours by the global motion compensation; and if the Gfs_flag signal has a logic value 0, it contains
M bits, M being equal to L, to define how close each of the
previous contours is to its corresponding current contour by
the global and local motion compensation, wherein if the
Contour_flag signal has a bit of a logic value 1, its
corresponding previous contour completely or partially
overlaps with one of the current contours in the preset search
range and, if otherwise, its corresponding previous contour
overlaps none of the current contours in the preset search
range.
Claim 8
Dependent Claim
141 words
The method according to claim 7, wherein the
Contour_flag_status signal includes two different bit streams
as: if the Gfs_flag signal has a logic value 1, it is
represented by N bits, N being equal to CPM, CPM being the
number of the previous contours which completely or partially
overlap with one of the current contours by the global and
local motion compensation except the previous contours
corresponding to GPM; and if the Gfs_flag signal has a logic value 0, it has N
bits, N being equal to CPM+GPM, each bit describing the
previous contours which completely or partially overlap with
their corresponding current contours by the global and local
motion compensation, wherein if the Contour_flag_status signal
has a bit of a logic value 1, its corresponding previous
contour completely overlaps with one of the current contours
in the preset search range.
Claim 9
Dependent Claim
39 words
The method according to claim 8, wherein, in the step (i),
the sequences of the errors and the local motion vectors for
the current frame follow the sequence of the index data
assigned to each of the previous contours.
Claim 10
Dependent Claim
41 words
The method according to claim 9, wherein, if there are
current contours overlapping none of the previous contours in
the preset search range, said current contours are intra-encoded
and the contour encoding information thereof has only
errors obtained by the intra-encoding.
Claim 11
Dependent Claim
49 words
The method according to claim 10, wherein, in the
sequence of the errors, errors for the current contours which
overlap none of the previous contours are sequentially
outputted according to a processing order of the current
contours in the current frame after errors for overlapping
current contours are outputted.
Claim 12
Independent Claim
345 words
An apparatus for encoding a contour of an object in a
current frame based on a previous frame, wherein the current
and the previous frames include one or more objects,
respectively, each of the objects having a contour, which
comprises: means for generating a global motion vector representing
a displacement between the current and the previous frames
which yields a largest number of overlapping object pixels
therebetween; means for detecting the contours of the objects in the
previous frame as previous contours, providing a contour
number representing the number of the previous contours, and
assigning index data to each of the previous contours in
response to a predetermined processing order; means for choosing one of the contours in the current
frame as a current contour; means for determining, for each of the current contours
in the current frame, an optimum contour among the previous
contours and setting a displacement between the current
contour and the optimum contour as a local motion vector(LMV),
the optimum contour being a contour among the previous
contours most similar to the current contour; means for producing, for said each of the current
contours, a predicted contour by shifting the optimum contour
based on the global and the local motion vectors; means for detecting, for said each of the current
contours, an error representing a difference between the
predicted contour and the current contour; means for generating flag signals describing how close
each of the previous contours is to a corresponding current
contour based on the contour number and contour encoding
information corresponding to said each of the current
contours, wherein the contour encoding information contains
the index data of the optimum contour, the error, and the
local motion vector; means for providing sequences of the errors and the local
motion vectors for the current frame based on the contour
encoding information corresponding to said each of the current
contours; and means for outputting encoded contour data of the current
frame by encoding the global motion vector, the sequences of
the errors and the local motion vectors, and the flag signals.
Claim 13
Dependent Claim
111 words
The apparatus as recited in claim 12, wherein the flag
signals generating means includes: means for providing, for each of the current contours, a
first state signal depicting whether the error has a zero
value or not and a second state signal representing whether
there is the LMV or not and, if there is the LMV, further
representing whether the LMV is a zero value or not; and means for producing the flag signals by determining, for
said each of the current contours, how close each of the
previous contours is to a corresponding current contour based
on the contour number, the index data, the first and the
second state signals.
Claim 14
Dependent Claim
211 words
The apparatus as recited in claim 13, wherein how close
each of the previous contours is to a corresponding current
contour is determined as: MATCHING DEGREE ERROR LMV INDEX DATA GM ZERO ZERO Y LM ZERO Y Y PM Y ZERO Y Y Y Y NM Y N N wherein the letter 'Y' represents that its corresponding value
has a non-zero value; the letter 'N' shows that its
corresponding value has no value; 'ZERO' depicts that its
corresponding value has a zero value; the matching degree GM
represents that a corresponding current contour perfectly
overlaps with one of the previous contours in a preset search
range by global motion compensation; the matching degree LM
illustrates that a corresponding current contour overlaps
perfectly with one of the previous contours in the preset
search range by global and local motion compensation; the
matching degree PM indicates that a corresponding current
contour overlaps partially with one of the previous contours
in the preset search range by the global and local motion
compensation; and the matching degree NM describes that a
corresponding current contour overlaps with none of the
previous contours in the preset search range, wherein the
states of the error and the LMV are represented by the first
and the second state signals.
Claim 15
Dependent Claim
148 words
The apparatus as recited in claim 14, wherein the flag
signals producing means includes: means for providing a Gfs_flag signal by comparing the
number of previous contours in the matching degree GM with a
predetermined threshold value; means for generating, in response to the Gfs_flag signal,
a Global_flag signal containing L bits, each bit having a
logic value 1 when its corresponding previous contour belongs
to the matching degree GM, L being the contour number; means for supplying, in response to the Gfs_flag signal,
a Contour_flag signal having M bits, each bit showing to which
one of the matching degrees its corresponding previous contour
belongs, M being a positive integer; and means for producing, in response to the Gfs_flag signal,
the Contour_flag_status signal containing N bits, N being a
positive integer, each bit illustrating whether its
corresponding previous contour belongs to either the matching
degree LM or PM.
Claim 16
Dependent Claim
41 words
The apparatus as recited in claim 15, wherein the
Gfs_flag signal has a logic value of: 1 if L < 4xGPM 0 if L ≥ 4xGPM wherein GPM is the number of the previous contours belonging
to the matching degree GM.
Claim 17
Dependent Claim
30 words
The apparatus as recited in claim 16, wherein if the
Gfs_flag signal has a logic value 1, the Global_flag signal is
generated and, if otherwise, the Global_flag signal is not.
Claim 18
Dependent Claim
138 words
The apparatus as recited in claim 17, wherein the
Contour_flag signal includes two different bit streams as: if the Gfs_flag signal is a logic value 1, it is
represented by M bits, M being equal to L-GPM, wherein each
bit describes each of the rest of previous contours except the
previous contours belonging to the matching degree GM; and if the Gfs_flag signal has a logic value 0, it contains
M bits, M being equal to L, to define how close each of the
previous contours is to its corresponding current contour by
the global and local motion compensation, wherein if the
Contour_flag signal has a bit of a logic value 1, its
corresponding previous contour belongs to the matching degree
GM, LM, or PM and, if otherwise, its corresponding previous
contour belongs to the matching degree NM.
Claim 19
Dependent Claim
112 words
The apparatus as recited in claim 18, wherein the
Contour_flag_status signal includes two different bit streams
as: if the Gfs_flag signal has a logic value 1, it is
represented by N bits, N being equal to CPM, CPM being the
number of the previous contours which belong to the matching
degree LM or PM and each bit having a logic value 1 when its
corresponding previous contour belongs to the matching degree
LM; and if the Gfs_flag signal has a logic value 0, it has N
bits, N being equal to CPM+GPM, each bit having a logic value
1 when its corresponding previous contour belongs to the
matching degree GM or LM.
Claim 20
Dependent Claim
36 words
The apparatus as recited in claim 19, wherein the
sequences of the errors and the local motion vectors for the
current frame follow the sequence of the index data assigned
to each of the previous contours.
Claim 21
Dependent Claim
38 words
The apparatus as recited in claim 20, wherein, if there
are the current contours belonging to the matching degree NM,
said current contours are intra-encoded and the contour
encoding information thereof has only errors obtained by the
intra-encoding.
Claim 22
Dependent Claim
53 words
The apparatus as recited in claim 21, wherein, in the
sequence of the errors, errors for current contours belonging
to the matching degree NM are sequentially outputted according
to a processing order of the current contours in the current
frame after errors for current contours belonging to the other
matching degrees are outputted.
References Cited (Backward Citations)
No citation records indexed.
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