EP0499307A1
Expired / Lapsed
EP
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Encoding circuit for transform coding of a picture signal and decoding circuit for decoding said signal
Assignee: Koninklijke Philips NV
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Filing: 1992-02-03
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Granted: —
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Expires: 2012-02-03
Abstract
Abstract Encoding circuit for transforming a picture signal into blocks of, for example, 8*8 coefficients, in which each block of coefficients is read motion-adaptively. In the case of motion within a sub-picture, the block of coefficients is read in such an order that the obtained series of coefficients comprises, as it were, two interleaved sub-series. The first series starts with a dc component. In a first embodiment the second series starts with the most relevant motion coefficient. In a second embodiment two interlaced sub-fields are separately transformed and the second series also starts with a dc coefficient. As a result the coefficients are transmitted as much as possible in their order of significance. This particularly produces the largest possible clusters of zero value coefficients. Such clusters are transmitted as one compact run-length code so that an effective bit rate reduction is achieved, also for moving pictures.
Inventors
- 👤 Peter Hendrik Nelis De With
- 👤 Stephanus Maria Christianus Borgers
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-02 10:49
CPC Classifications
H; H04; H04N; H04N5/00; H04N5/76; H04N19/00; H04N19/10; H04N19/102; H04N19/124; H04N19/126; H04N19/103; H04N19/112; H04N19/60; H04N19/132; H04N5/91; H04N5/92; H04N5/926; H04N5/9261; H04N5/9264
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
108 words
An encoding circuit for transform coding of a picture signal, comprising: - means for partitioning pictures into sub-pictures, - a transform circuit for transforming each sub-picture into a two-dimensional block of contiguous coefficients, - a motion detector receiving the sub-pictures and generating a motion signal when noticeable motion has been detected within the sub-picture, - scanning means for reading the block of coefficients in accordance with a scanning pattern dependent on the motion signal and for converting them into a serial sequence of coefficients, characterized in that the scanning pattern provides at least one jump to a predetermined coefficient which is not contiguous to a previously read coefficient.
Claim 2
Dependent Claim
24 words
An encoding circuit as claimed in Claim 1, characterized in that the predetermined coefficient is representative of the presence of motion in the sub-picture.
Claim 3
Dependent Claim
54 words
An encoding circuit as claimed in Claim 1, in which the sub-picture comprises two interlaced sub-fields, characterized in that the transform circuit is adapted to partition the block of coefficients into sub-blocks by separately transforming the sub-fields and in that the predetermined coefficient forms part of a different sub-block than the previously read coefficients.
Claim 4
Dependent Claim
22 words
An encoding circuit as claimed in Claim 3, characterized in that the predetermined coefficient is the dc coefficient of the relevant sub-block.
Claim 5
Dependent Claim
28 words
An encoding circuit as claimed in Claim 3, characterized in that the scanning means are further adapted to read the separate sub-blocks in accordance with a zigzag pattern.
Claim 6
Dependent Claim
25 words
An encoding circuit as claimed in Claim 3, characterized in that the scanning means are further adapted to read coefficients of the two sub-blocks alternately.
Claim 7
Dependent Claim
38 words
An encoding circuit as claimed in Claim 3, characterized in that it is further provided with means for converting the dc coefficients of the two sub-blocks into a difference coefficient which represents the difference of said dc coefficients.
Claim 8
Dependent Claim
101 words
A decoding circuit for decoding a transformed picture signal supplied by an encoding circuit as claimed in Claim 1 or 2, comprising: - means for regenerating the motion signal, - storage means for storing a serial sequence of coefficients in accordance with a storage pattern dependent on the motion signal in a two-dimensional block of contiguous addressable memory locations, - an inverse transform circuit for transforming the coefficients stored in the block into a sub-picture, characterized in that the storage pattern jumps by at least one step to a predetermined memory location which is not contiguous to previously addressed memory locations.
Claim 9
Dependent Claim
75 words
A decoding circuit as claimed in Claim 8 for decoding a transformed picture signal which is supplied by an encoding circuit as claimed in any one of Claims 3-6, characterized in that the inverse transform circuit is adapted to partition the block of coefficients into two sub-blocks and to transform them separately into two interlaced sub-fields, and in that the predetermined memory location forms part of a different sub-block than the previously addressed memory locations.
Claim 10
Dependent Claim
45 words
A decoding circuit as claimed in Claim 9 for decoding a transformed picture signal from an encoding circuit as claimed in Claim 7, characterized in that the decoding circuit is further provided with means for regaining the two dc coefficients from the received difference coefficient.
Claim 11
Dependent Claim
17 words
A transmitter of television signals, including an encoding circuit as claimed in any one of Claims 1-7.
Claim 12
Dependent Claim
17 words
A receiver of television signals, including a decoding circuit as claimed in Claim 8, 9 or 10.
Claim 13
Dependent Claim
33 words
A video recorder for recording and displaying televison signals, including an encoding circuit as claimed in any one of Claims 1-7 and a decoding circuit as claimed in Claim 8, 9 or 10.
Claim 14
Dependent Claim
28 words
An encoding circuit as claimed in Claim 6, chararacterized in that the scanning means are adapted to read coefficients according to the scanning pattern shown in Figure 12.
References Cited (Backward Citations)
WO1987002854A1
Cited
US4849812A
Cited
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