Method and apparatus for efficiently communicating image sequence having improved motion compensation

An image sequence communications apparatus for communicating a sequence of images over a communications channel, said apparatus comprising

• a transmitter having
• means for estimating, for successive images of the sequence, a measure of the motion displacement of block regions of an image,
• coding means for representing said generated measures of an image as a coded motion signal representation,
• means for generating, using said coded motion signal representation and an estimated previous receiver image, an error reconstruction signal, and
• means for transmitting said coded motion signal representation and said error reconstruction signal over said channel, and
• a receiver having
• means for constructing an error image representation from a received error reconstruction signal,
• means for constructing a motion field measure from a received coded motion signal representation, and
• means responsive to said received error image representation and said receiver motion field measure for generating a reconstructed image sequence,
• wherein said error reconstruction signal generating means includes an improved error signal generating means comprising
• A. a motion reconstruction means for generating motion reconstruction displacement signals for each block in response to said coded motion signal representation,
• B. a transmitter motion field interpolation means for generating, in response to said displacement signals, a displacement vector for each picture element of a said image, and
• C. a motion compensation means responsive to said motion field interpolation means for modifying said receiver estimated previous image for constructing an estimated receiver image, and
• wherein said reconstructed image sequence generating means includes an improved receiver generating means comprising
• D. a receiver motion field interpolation means for generating, in response to said received coded motion signal representation, a displacement vector for each picture element of an image to be constructed, and
• E. a received motion compensation loop means responsive to said motion field interpolator and said error reconstructing means for generating an image sequence.

An image sequence transmission method for transmitting a sequence of images over a communications channel having the steps of

• estimating, for successive images of the sequence, a measure of the motion displacement of block regions of an image,
• representing said generated measures of an image as a coded motion signal representation,
• generating, using said coded motion signal representation and an estimated previous receiver image, an error reconstruction signal for said image, and
• transmitting over the channel the coded motion signal representation and the error reconstruction signal,
• wherein said error reconstruction signal generating step includes an improved error signal generating method comprising the steps of
• A. generating motion block reconstruction displacement signals in response to the coded motion signal representation,
• B. interpolating, in response to said block reconstruction displacement signals, a displacement vector for each picture element of said image, and
• C. constructing an estimated receiver image from the interpolated motion reconstruction signal and said receiver estimated previous image.

An image sequence communications method for communicating a sequence of images over a communications channel including the steps of

• estimating, for successive images, a measure of the motion displacement of block regions of an image,
• representing said generated measures of an image as a coded motion signal representation,
• generating, using said coded signal representation and a receiver estimated previous image, an error reconstruction signal,
• transmitting said coded motion signal representation and said error reconstruction signal over said channel,
• constructing, at a receiver, an error image representation from a receiver error reconstruction signal,
• constructing, at the receiver, a motion field measure from a received coded motion signal representation, and
• generating a reconstructed image sequence from the receiver error representation and receiver motion field measure,
• wherein said error reconstruction signal generating step includes an improved error signal generating method comprising the steps of
• A. generating motion block reconstruction displacement signals in response to the coded motion signal representation,
• B. interpolating, in response to said block reconstruction displacement signals, a displacement vector for each picture element of said image, and
• C. constructing an estimated receiver image from the interpolated motion reconstruction signal and said receiver estimated previous image, and
• wherein said reconstructed image sequence generating step includes an improved receiver generating method comprising the steps of
• D. interpolating said received coded motion signal representation of said block displacements for generating a displacement vector for each picture element of an image to be constructed, and
• E. generating an image sequence from the interpolated motion field and the error representation.