Video conferencing system with high resolution still image capability
AssigneeSony Corporation
InventorKatsumi Tahara
Life of this patent
Estimating the term…
Abstract
Image data of four frames are stored in four memories and the image data from the four memories are sequentially transmitted, whereby still picture image data having a resolution twice the resolution of a common intermediate format (CIF) image based on the video CODEC recommendation H.261 can be transmitted.
Claims17
An apparatus for compressing a digital image signal representing both motion picture and still picture digital data so that a common transmission format is used for both of compressed motion picture and compressed still picture digital data, comprising:
- means for selecting one of a motion picture mode and a still picture mode;
- means for sampling, when the still picture mode is selected, said still picture digital data representing a high resolution video image in accordance with a plurality of sampling clocks having different phases to produce a plurality of sample digital image signals;
- storing means for storing each of said sample digital image signals, said storing means including a plurality of frame memories each for storing a respective one of said sample digital image signals and for reading out the respective stored sample digital image signal as a respective sample output signal;
- and
- means for compressing the sample output signals by producing a plurality of difference signals each representing a difference between sample digital image signals stored in respective successive frame memories, said difference signals forming said compressed still picture digital data which can be transmitted through a transmission channel having a predetermined transmission capacity.
An apparatus for decompressing a compressed digital image signal representing both standard resolution motion picture and high resolution still picture compressed digital data in a common transmission format and received through a reception channel having a predetermined reception capacity, comprising:
- means for decompressing the compressed digital image signal to produce a recovered digital image signal, said recovered digital image signal representing a high resolution still picture being comprised of standard resolution frames representing samples of said high resolution still picture at respectively different phases, some of said standard resolution frames including difference data representing correlations between respective successive standard resolution frames;
- means for extracting an indicator of one of a motion picture mode and a still picture mode from said compressed digital image signal;
- means for storing said standard resolution frames of said recovered digital image signal when the still picture mode is indicated;
- and
- means for reading the stored standard resolution frames of said recovered digital image signal from said means for storing to produce a high resolution still picture.
An apparatus for decompressing a compressed digital image signal representing both motion picture and still picture compressed digital data in a common transmission format and received through a reception channel having a predetermined reception capacity, comprising:
- means for decompressing the compressed digital image signal to produce a recovered digital image signal, said recovered digital image signal representing a still picture being comprised of standard resolution frames representing samples of said still picture at respectively different phases, some of said standard resolution frames including difference data representing correlations between respective successive standard resolution frames;
- means for extracting an indicator of one of a motion picture mode and a still picture mode from said compressed digital image signal;
- and
- means for storing said recovered digital image signal when the still picture mode is indicated, said means for storing including a plurality of frame memories each of which stores a respective one of said standard resolution frames.
An apparatus for decompressing a compressed digital image signal representing both motion picture and still picture compressed digital data in a common transmission format and received through a reception channel having a predetermined reception capacity, comprising:
- means for decompressing the compressed digital image signal to produce a recovered digital image signal, said recovered digital image signal representing a high resolution still picture being comprised of standard resolution frames representing samples of said high resolution still picture at respectively different phases, some of said standard resolution frames including difference data representing correlations between respective successive standard resolution frames;
- means for extracting an indicator of one of a motion picture mode and a still picture mode from said compressed digital image signal;
- means for storing each of said standard resolution frames when the still picture mode is indicated;
- and
- selector means for preventing said standard resolution frames of said recovered digital image signal from being stored in said means for storing when the motion picture mode is indicated.
A method for compressing a digital image signal representing both motion picture and still picture digital data so that a common transmission format is used for both of compressed motion picture and compressed still picture digital data, comprising the steps of:
- selecting one of a motion picture mode and a still picture mode;
- sampling, when the still picture mode is selected, said still picture digital data representing a high resolution video image in accordance with a plurality of sampling clocks having different phases to produce a plurality of sample digital image signals;
- storing each of said sample digital image signals in a plurality of frame memories each for storing a respective one of said sample digital image signals and for reading out the respective stored sample digital image signal as a respective sample output signal;
- and
- compressing the sample output signals by producing a plurality of difference signals each representing a difference between sample digital image signals stored in respective successive frame memories, said difference signals forming said compressed still picture digital data which can be transmitted through a transmission channel having a predetermined transmission capacity.
A method for decompressing a compressed digital image signal representing both standard resolution motion picture and high resolution still picture compressed digital data in a common transmission format and received through a reception channel having a predetermined reception capacity, comprising the steps of:
- decompressing the compressed digital image signal to produce a recovered digital image signal, said recovered digital image signal representing a high resolution still picture being comprised of standard resolution frames representing samples of said high resolution still picture at respectively different phases, some of said standard resolution frames including difference data representing correlations between respective successive standard resolution frames;
- extracting an indicator of one of a motion picture mode and a still picture mode from said compressed digital image signal;
- storing said standard resolution frames of said recovered digital image signal when the still picture mode is indicated;
- and
- reading the stored standard resolution frames of said recovered digital image signal to produce a high resolution still picture.
An apparatus for compressing a digital image signal representing both motion picture and high resolution still picture digital data so that a common transmission format is used for both of compressed motion picture and compressed still picture digital data, comprising:
- means for selecting one of a motion picture mode and a still picture mode;
- means for sampling, when the still picture mode is selected, said still picture digital data representing a high resolution video image in accordance with a plurality of sampling clocks having different phases to produce a plurality of sample digital image signals;
- storing means for storing each of said sample digital image signals, said storing means including a plurality of frame memories each having a capacity of one frame of a standard resolution signal for storing a respective one of said sample digital image signals and for reading out the respective stored sample digital signal as a respective sample output signal;
- and
- means for compressing the sample output signals by producing a plurality of difference signals each representing a difference between sample digital image signals stored in respective successive frame memories, said difference signals forming said compressed still picture digital data which can be transmitted through a transmission channel having a predetermined transmission capacity.
A method for compressing a digital image signal representing both motion picture and high resolution signal still picture digital data so that a common transmission format is used for both of compressed motion picture and compressed still picture digital data, comprising the steps of:
- selecting one of a motion picture mode and a still picture mode;
- sampling, when the still picture mode is selected, said still picture digital data representing a high resolution video image in accordance with a plurality of sampling clocks having different phases to produce a plurality of sample digital image signals;
- storing said sample digital image signals in a plurality of frame memories each having a capacity of one frame of a standard resolution signal for storing a respective one of said sample digital image signals and for reading out the respective stored sample digital signal as a respective output signal;
- and
- compressing the sample output signals by producing a plurality of difference signals each representing a difference between sample digital image signals stored in respective successive frame memories, said difference signals forming said compressed still picture digital data which can be transmitted through a transmission channel having a predetermined transmission capacity.
A method for decompressing a compressed digital image signal representing both motion picture and still picture compressed digital data in a common transmission format and received through a reception channel having a predetermined reception capacity, comprising the steps of:
- decompressing the compressed digital image signal to produce a recovered digital image signal, said recovered digital image signal representing a high resolution still picture being comprised of standard resolution frames representing samples of said high resolution still picture at respectively different phases, some of said standard resolution frames including difference data representing correlations between respective successive standard resolution frames;
- extracting an indicator of one of a motion picture mode and a still picture mode from said compressed digital image signal;
- and
- storing each of said standard resolution frames of said recovered digital image signal in a respective one of a plurality of frame memories when the still picture mode is indicated.
An apparatus for compressing a digital signal representing a high resolution video image, comprising:
- means for receiving said digital signal representing a high resolution video image;
- means for sampling said digital signal using a plurality of sampling clocks having respectively different phases to produce a plurality of sample digital signals, each of said sample digital signals representing a respective lower resolution video image;
- a plurality of storage means each for storing a respectively different one of said sample digital signals;
- means for differencing at least one of said sample digital signals stored in the respective storage means with a different one of said sample digital signals to produce a difference signal;
- and
- means for outputting said difference signal as a compressed digital signal.
Dependencies are inferred from the claim text.