Pulse or digital communications – Bandwidth reduction or expansion – Television or motion video signal
Reexamination Certificate
1994-11-07
2001-04-24
Rao, Andy (Department: 2613)
Pulse or digital communications
Bandwidth reduction or expansion
Television or motion video signal
C375S240020, C375S240040
Reexamination Certificate
active
06222881
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to signal processing, and, in particular, to computer-implemented processes and apparatuses for encoding and decoding video signals.
2. Description of the Related Art
This invention relates to audio/video conferencing between two or more conference nodes, where each conference node is a personal computer (PC) system communicating with the other conference nodes over a selected transmission medium. Because transmission media typically have finite bandwidths, in order to provide audio/video conferencing of satisfactory quality, each PC system preferably compresses in real time the audio and video signals corresponding to the local participant and transmits the resulting compressed signals to the PC systems of the remote participants. Each PC system also preferably receives and decompresses compressed signals from the PC systems of the remote participants to play the decompressed audio and video signals locally.
Possible transmission media include Integrated Services Digital Network (ISDN) and Public Switched Telephone Network (PSTN) telephone connections. Although ISDN connections provide a higher bandwidth than PSTN connections, ISDN connections are less readily available and more expensive than PSTN connections.
Unfortunately, conventional methods for compressing video signals, such as the H.261 (P×64) and ISO/IEC 11172-2 (MPEG) standards, require bandwidths greater than that provided by PSTN connections. As a result, these conventional video compression methods cannot be used to support audio/video conferencing over PSTN connections.
What is needed is a video compression process that can be implemented in real time on PC systems to generate compressed video signals that can be transmitted under the bandwidth constraints of PSTN connections and then decompressed in real time by the PC systems to provide satisfactory audio/video conferencing.
It is accordingly an object of this invention to overcome the disadvantages and drawbacks of the known art and to provide computer-implemented processes, apparatuses, and systems for compressing and decompressing video signals to provide satisfactory audio/video conferencing between PC systems communicating via PSTN connections.
Further objects and advantages of this invention will become apparent from the detailed description of a preferred embodiment which follows.
SUMMARY OF THE INVENTION
The present invention is a computer-implemented process and apparatus for encoding video signals. According to a preferred embodiment, a transform is applied to a region of a current video frame to generate transform signals corresponding to the region. An activity measure is generated using the transform signals. The activity measure is used to determine whether to encode the region as a skipped region. The region is encoded in accordance with that determination to generate an encoded bit stream for the region.
REFERENCES:
patent: 4827338 (1989-05-01), Gerard
patent: 4893123 (1990-01-01), Boisson
patent: 4933761 (1990-06-01), Murakami et al.
patent: 4953019 (1990-08-01), Skikakura et al.
patent: 5025482 (1991-06-01), Murakami et al.
patent: 5038209 (1991-08-01), Hang
patent: 5046071 (1991-09-01), Tanoi
patent: 5063608 (1991-11-01), Siegel
patent: 5097330 (1992-03-01), Guichard et al.
patent: 5121216 (1992-06-01), Chen et al.
patent: 5122877 (1992-06-01), Keesman
patent: 5134476 (1992-07-01), Aravind et al.
patent: 5136371 (1992-08-01), Savatier et al.
patent: 5144426 (1992-09-01), Tanaka et al.
patent: 5150209 (1992-09-01), Baker et al.
patent: 5177608 (1993-01-01), Ohki et al.
patent: 5214507 (1993-05-01), Aravind et al.
patent: 5265180 (1993-11-01), Golin
patent: 5267334 (1993-11-01), Normille et al.
patent: 5301018 (1994-04-01), Smidth et al.
patent: 5301242 (1994-04-01), Gonzales et al.
patent: 5311310 (1994-05-01), Jozawa et al.
patent: 5313298 (1994-05-01), Meeker
patent: 5317397 (1994-05-01), Odaka et al.
patent: 5333012 (1994-07-01), Singhal et al.
patent: 5351085 (1994-09-01), Coelho et al.
patent: 5365271 (1994-11-01), Asano
patent: 5367629 (1994-11-01), Chu et al.
patent: 5410351 (1995-04-01), Kojima
patent: 5416521 (1995-05-01), Chujoh et al.
patent: 5418569 (1995-05-01), Ando
patent: 5434623 (1995-07-01), Coleman et al.
patent: 5440344 (1995-08-01), Asamura et al.
patent: 5440345 (1995-08-01), Shimoda
patent: 5440346 (1995-08-01), Alattar et al.
patent: 5461421 (1995-10-01), Moon
patent: 5461422 (1995-10-01), Hsieh
patent: 5473377 (1995-12-01), Kim
patent: 5475433 (1995-12-01), Jeong
patent: 5489944 (1996-02-01), Jo
patent: 5502491 (1996-03-01), Sugiyama et al.
Kronander, “Post- and Pre-Processing in Coding of Image Sequences Using Filters with Motion Compensated History” 1988 Int. Conf. Acoustics, Speech. Sig. Processing, vol. 2, Apr. 1988, pp. 1104-1107.
Duane Morris & Heckscher LLP
Intel Corporation
Rao Andy
LandOfFree
Using numbers of non-zero quantized transform signals and... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Using numbers of non-zero quantized transform signals and..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Using numbers of non-zero quantized transform signals and... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2512368