Video conferencing with video accumulator array VAM memory

• US 6,348,946 B1
• Filed: 08/14/1997
• Issued: 02/19/2002
• Est. Priority Date: 08/14/1997
• Status: Expired due to Term

• Current Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Original Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Inventors: Caci, Joseph Claude
• Primary Examiner(s): HO, TUAN V
• Application Number:
  US08/911,600
• Time in Patent Office: 1,650 Days
• Field of Search: H04/N.5202, 348/362, 348/379, 348/256, 348/364, 348/254, 348/229, 348/230, 348/255, 348/234, 348/235, 348/236, 348/237, 348/238, 348/272, 348/674, 348/675, 348/370, 348/342, 348/166, 358/455
• US Class Current: 348/254
• CPC Class Codes: G06T 1/60 Memory management

Abstract

In a video conferencing system, digital data representing pixels of a selected scene are stored in a Video accumulator Array Memory cells (VAM), each cell having memory with several register structures and having the capability of processing the digital data to facilitate compression of the digital data. The VAM has the ability to tell the processor information about the temporal nature of the video data without requiring the processor to first read the data and then test the data. In accordance with the present invention, the capability of processing the video data is designed directly in the memory function as they are stored. The memory array, by providing a capacity of temporal processing wherein the digital data in one video frame can be logically interacted with another video frame later in time, can make a significant reduction in the bandwidth required to transmit a video frame. In a scheme for representing gray scale luminosity, the luminosity is digitally represented by the plus and minus differences from the mid point of the gray scale. A color video camera, in addition to generating color separation pixel values, also generates gray scale luminosity values which include a steady state infrared component provided by steady sate illumination of scene in order to reduce the adverse effects of fluorescent lighting.

Claims

1. A method of digitally representing video data comprising generating analog values representing luminosity of pixels of a detected scene, wherein said analog values potentially range from a minimum magnitude to a maximum magnitude to represent luminosities in said detected scene potentially ranging from a minimum luminosity to a maximum luminosity, converting said analog values to digital values, wherein the luminosity in said detected scene at the midpoint between said maximum and said minimum luminosity is represented with a digital value of zero and digitally representing other luminosities in said detected scene as plus or minus differences in the luminosity from said midpoint.

2. A method as recited in claim 1 wherein the least significant bit of a first luminosity value of a block of adjacent pixels having luminosities on the same side of said midpoint represents the sign of the luminosity of all the pixels of said block.

3. A video system comprising a video camera adapted to detect analog values to represent color separations of pixels of a scene being televised, said camera including a detector and being operable to image a color-neutral image of said scene on said detector, said detector detecting said color-neutral image to generate analog values representing the gray scale luminosity of pixels said scene, and an analog-to-digital converter connected to said camera to convert said analog values to digital values to generate sets of digital values representing color separations of said scene in pixel form, and to generate digital values representing the gray scale luminosity of said scene in pixel form, and a Video accumulator Array Memory (VAM) storing said digital values.

4. A video system comprising a video camera adapted to detect analog values to represent color separations of pixels of a scene being televised, and to generate analog values representing the gray scale luminosity of said scene, an analog-to-digital converter connected to said camera to convert said analog values to digital values to generate sets of digital values representing color separations of said scene in pixel form, and to generate digital values representing the gray scale luminosity of said scene in pixel form, a Video accumulator Array Memory (VAM) storing said digital values and a man made infrared light source arranged to illuminate said scene with infrared light so that said gray scale luminosity values include a component corresponding to the infrared illumination of said scene.