Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
181 words
A method for use in a digitized video signal decoder having first and second decoding means, for providing a main picture and a picture-in-picture simultaneously on a screen from a plurality of digital video signals received from transmitters, wherein each of the digital video signals received has been compressed by using a coding technique involving a motion-compensated differential pulse code modulation and two dimensional discrete cosine transform, the first decoding means includes a first frame memory for storing current and previous frames of the main picture, and the second decoding means includes a second frame memory for storing current and previous frames of the picture-in-picture, said method comprising the steps of: selecting a main picture signal and a picture-in-picture signal from the plurality of digital video signals; decoding the main picture signal at the first decoding means; decoding the picture-in-picture signal at the second decoding means by using a set of reduced motion vectors and a reduced number of transform coefficients; and providing a composite image of the main picture and the picture-in-picture from the first and the second frame memories.
Claim 2
Independent Claim
181 words
A method for use in a digitized video signal decoder having first and second decoding means, for providing a main picture and a picture-in-picture simultaneously on a screen from a plurality of digital video signals received from transmitters, wherein each of the digital video signals received has been compressed by using a coding technique involving a motion-compensated differential pulse code modulation and two dimensional discrete cosine transform, the first decoding means includes a first frame memory for storing current and previous frames of the main picture, and the second decoding means includes a second frame memory for storing current and previous frames of the picture-in-picture, said method comprising the steps of: selecting a main picture signal and a picture-in-picture signal from the plurality of digital video signals; decoding the main picture signal at the first decoding means; decoding the picture-in-picture signal at the second decoding means by using a set of reduced motion vectors and a reduced number of transform coefficients; and providing a composite image of the main picture and the picture-in-picture from the first and the second frame memories.
Claim 3
Dependent Claim
164 words
The method according to claim 1, wherein said step of decoding the main picture signal includes the steps of: converting said main picture signal into first multiple sets of P×Q transform coefficients and a first multiple number of motion vectors, wherein each of the first multiple number of motion vectors corresponds to each set of the first multiple sets of P×Q transform coefficients, P and Q being positive integers; generating a block of P×Q pixel difference data from each set of the first multiple sets of P×Q transform coefficients; deriving a block of P×Q pixel data corresponding to each of the first multiple number of motion vectors from the previous frame stored in the first frame memory; reconstructing a block of P×Q pixel data of the current frame from the block of P×Q pixel difference data and the block of P×Q pixel data from the previous frame; and storing the block of P×Q pixel data of the current frame in the first frame memory.
Claim 4
Dependent Claim
249 words
The method according to claim 1, wherein said step of decoding the picture-in-picture signal includes the steps of: converting said picture-in-picture signal into second multiple sets of P×Q transform coefficients and a second multiple number of motion vectors, wherein each of the second multiple number of motion vectors MV corresponds to each set of the second multiple sets of P×Q transform coefficients and consists of a horizontal vector component MVH and a vertical vector component MVV; providing multiple subsets of P/N×Q/N transform coefficients including a d.c. coefficient, each of the multiple subsets being derived from each of the second multiple sets of P×Q transform coefficients, wherein P/N and Q/N are integers with N being a reduction ratio for the picture-in-picture with respect to both the horizontal and the vertical sizes of the screen; generating a block of P/N×Q/N pixel difference data from one set of the multiple subsets of P/N×Q/N transform coefficients; modifying each of the second multiple number of motion vectors MV into a reduced motion vector MV/N consisting of reduced horizontal and vertical vector components MVH/N and MVV/N; deriving a block of P/N×Q/N interpolated pixel data corresponding to the reduced motion vector MV/N from the previous frame stored in the second frame memory; reconstructing a block of P/N×Q/N pixel data of the current frame from the block of P/N×Q/N pixel difference data and the block of P/N×Q/N interpolated pixel data; and storing the block of P/N×Q/N pixel data of the current frame in the second frame memory.
Claim 5
Dependent Claim
95 words
The method according to claim 3, wherein each of the P/N×Q/N interpolated pixel data is determined by a pixel represented by the reduced motion vector MV if both of the reduced vector components MVH/N and MVV/N thereof are integers; by two closest pixels to a location represented by the reduced motion vector MV if only one of the reduced vector components MVH/N and MVV/N is an integer; and by four closets pixels to a location represented by the reduced motion vector MV if none of the reduced vector components MVH/N and MVV/N is an integer.
Claim 6
Dependent Claim
13 words
The method according to claim 4, wherein P and Q are 8, respectively.
Claim 7
Independent Claim
164 words
An apparatus for use in a digitized video signal decoder for providing a main picture and a picture-in-picture simultaneously on a screen from a plurality of digital video signals received from transmitters, wherein each of the digital video signals has been compressed by using a coding technique involving a motion-compensated differential pulse code modulation and two dimensional discrete cosine transform, said apparatus comprising: means for selecting a main picture signal and a picture-in-picture signal from the plurality of digital video signals; first means for decoding the main picture signal, which includes a first frame memory for storing current and previous frames of the main picture; second means for decoding the picture-in-picture signal by using a set of reduced motion vectors and a reduced number of transform coefficients, which includes a second frame memory for storing current and previous frames of the picture-in-picture; and means for providing a composite image of the main picture and the picture-in-picture from the first and the second frame memories.
Claim 8
Independent Claim
164 words
An apparatus for use in a digitized video signal decoder for providing a main picture and a picture-in-picture simultaneously on a screen from a plurality of digital video signals received from transmitters, wherein each of the digital video signals has been compressed by using a coding technique involving a motion-compensated differential pulse code modulation and two dimensional discrete cosine transform, said apparatus comprising: means for selecting a main picture signal and a picture-in-picture signal from the plurality of digital video signals; first means for decoding the main picture signal, which includes a first frame memory for storing current and previous frames of the main picture; second means for decoding the picture-in-picture signal by using a set of reduced motion vectors and a reduced number of transform coefficients, which includes a second frame memory for storing current and previous frames of the picture-in-picture; and means for providing a composite image of the main picture and the picture-in-picture from the first and the second frame memories.
Claim 9
Dependent Claim
166 words
The apparatus according to claim 6, wherein said first decoding means includes: means for converting the main picture signal into first multiple sets of P×Q transform coefficients and a first multiple number of motion vectors, wherein each of the first multiple number of motion vectors corresponds to each set of the first multiple sets of P×Q transform coefficients, P and Q being positive integers; means for generating a block of P×Q pixel difference data from each set of the first multiple sets of P×Q transform coefficients; means for deriving a block of P×Q pixel data corresponding to each of the first multiple number of motion vectors from the previous frame stored in the first frame memory; and means for reconstructing a block of P×Q pixel data of the current frame from the block of P×Q pixel difference data and the block of P×Q pixel data from the previous frame and providing the block of P×Q pixel data of the current frame to the first frame memory.
Claim 10
Dependent Claim
252 words
The apparatus according to claim 6, wherein said second decoding means includes: means for converting the picture-in-picture signal into second multiple sets of P×Q transform coefficients and a second multiple number of motion vectors, wherein each of the second multiple number of motion vectors MV corresponds to each set of the second multiple sets of P×Q transform coefficients and consists of a horizontal vector component MVH and a vertical vector component MVV; means for providing multiple subsets of P/N×Q/N transform coefficients including a d.c. coefficient, each of the multiple subsets being derived from each of the second multiple sets of P×Q transform coefficients, wherein P/N and Q/N are integers with N being a reduction ratio for the picture-in-picture with respect to both the horizontal and the vertical sizes of the screen; means for generating a block of P/N×Q/N pixel difference data from said subset of P/N×Q/N transform coefficients; means for modifying each of the second multiple number of motion vectors MV into a reduced motion vector MV/N consisting of reduced horizontal and vertical vector components MVH/N and MVV/N; means for deriving a block of P/N×Q/N interpolated pixel data corresponding to the reduced motion vector MV/N from the previous frame stored in the second frame memory; and means for reconstructing a block of P/N×Q/N pixel data of the current frame from the block of P/N×Q/N pixel difference data and the block of P/N×Q/N interpolated pixel data and providing the block of P/N×Q/N pixel data of the current frame to the second frame memory.
Claim 11
Dependent Claim
96 words
The apparatus according to claim 8, wherein each of the P/N ×Q/N interpolated pixel data is determined by a pixel represented by the reduced motion vector MV if both of the reduced vector components MVH/N and MVV/N thereof are integers; by two closest pixels to a location represented by the reduced motion vector MV if only one of the reduced vector components MVH/N and MVV/N is an integer; and by four closets pixels to a location represented by the reduced motion vector MV if none of the reduced vector components MVH/N and MVV/N is an integer.
Claim 12
Dependent Claim
13 words
The apparatus according to claim 9, wherein P and Q are 8, respectively.