Software video compression for teleconferencing

DETAILED DESCRIPTION What is claimed is: 1.
A computer-implemented method for producing a video signal for transmission, in a system having a source of a first video signal comprised of sequential frames of signals, comprising transmitting video signals at least partially with lossy compression, corresponding to a sequence of said sequential frames of signals; storing a frame of signals corresponding to a composite of signals that have been transmitted in said step of transmitting video signals corresponding to a sequence of sequential frames; comparing blocks of said stored frame of signals with corresponding blocks of a video frame that occurs subsequent said sequence; identifying blocks of said stored frame that differ in information content from blocks of said video frame by more than a predetermined extent; transmitting said identified blocks of said video frame with lossy compression; and modifying blocks of said stored frame to conform to data of said identified blocks of data transmitted in said step of transmitting with lossy compression.
2.
The method of claim 1 further comprising determining the time required for transmitting said identified blocks with lossy compression; and transmitting data of said blocks of said video frame that were not identified in said step of comparing for a duration corresponding to a predetermined proportion of said determined time.
3.
A computer-implemented method for producing a video signal for transmission, in a system having a source of a first video signal comprised of sequential frames of signals, each frame being comprised of pixel signals numerically representing visual characteristics of separate pixels of the respective frame: comprising storing pixel signals of a plurality of separate first blocks of a first frame of video signals to define a plurality of separate first n.
times.
m matrices of first pixel signals representing rows and columns, respectively, of a respective block of said first frame, wherein n and m are integers; storing a plurality of second blocks of pixel signals of a frame of second video signals corresponding to a frame of said first video signal to define a plurality of separate second n