Video telephone systems

Details Video telephone systems Video telephone systems

1994-09-02

1996-08-06

Coles, Sr., Edward L.

Facsimile and static presentation processing

Facsimile

Reduced time or bandwidth for static image communication

358429, 358455, 358457, 358458, 358466, 348407, 348415, H04N 141, H04N 140, H04N 712, H04N 1102

Patent

active

055439390

ABSTRACT:
Differential image data compression systems and techniques are disclosed for use in video telephone systems for full duplex, real time transmission of audio and video images over nominal 3 kHz residential telephone lines and other narrow bandwidth channels. Each video telephone device consists of a transmitting portion and a receiving portion. In the transmitting section a reduced grey-scale (luminance) image, preferably consisting of only black-and-white pixels, is compared in an image processing module with a similarly reduced image derived from previous values to determine pixel positions that have changed. Information representative of the changes is then encoded and modulated and (time or frequency) multiplexed with the audio and/or chrominance signals for transmission. At the receiver, the incoming signal is demodulated and demultiplexed to separate the audio and video portions, the image portion is decoded and the luminance value is updated by an image updating unit. Adaptive resolution, pixel averaging and interpolation techniques are also disclosed for picture enhancement.

REFERENCES:
patent: 3937878 (1976-02-01), Judice
patent: 3959583 (1976-05-01), Fudice et al.
patent: 3962535 (1976-06-01), Haskell
patent: 3974325 (1976-08-01), Wilmer
patent: 4266249 (1981-05-01), Chai et al.
patent: 4546383 (1985-10-01), Abramatic et al.
patent: 4591907 (1986-05-01), Catros
patent: 4613894 (1986-09-01), Catros
patent: 4630125 (1986-12-01), Roetling
patent: 4654484 (1987-03-01), Reiffel et al.
patent: 4667247 (1987-05-01), Karow
patent: 4703348 (1987-10-01), Yuasa et al.
patent: 4713688 (1987-12-01), Guttner
patent: 4717957 (1988-01-01), Santamaki et al.
patent: 4758893 (1988-07-01), Lippel
patent: 4766499 (1988-08-01), Inuzuka
patent: 4816901 (1989-03-01), Music et al.
patent: 4821119 (1989-04-01), Gharavi
patent: 4967272 (1990-10-01), Kao et al.
Pratt, Digital Image Processing, pp. 593-598.
Ochi et al., "A New Halftone Reproduction and Transmission Method Using Standard Black and White Facsimile Code" (1987), vol. COM-35, pp. 466-470.
Gharavi, "Conditional Run-Length and Variable-Length Coding of Digital Pictures" (1987), vol. COM-35, No. 6, pp. 671-677.
Lin and Costello, "Error Control Coding Fundamentals and Applications", (1983), pp. vii-xi, and 257-295.
Hecht et al. "Delay Modulation" (1969), vol. 57, pp. 1314-1316.
Kim et al., "Video Telephone: Gone Today Here Tomorrow?" (1986), vol. 15, No. 12, pp. 124-128, 131-132 and 135-136.
Mosley, "Widespread Graphics Use Spawns Diversity In Data-Compression Devices" (1988), pp. 87-94.
Mitsubishi, "Affordable Picturephone" (1989), p. 26.
Mitsubishi, "Now, The Telephone Lets You See Who's Talking" (1989).
Image Data Corporation, "The Photophone" (1989).
Eckhouse, "Facing The Phones" (1987), pp. 48-51.

Affiliated with

Also associated with

Rating

Video telephone systems does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Video telephone systems, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Video telephone systems will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2195370