Method and Apparatus For The Identification and Selective Encoding of Changed Host Display Information

Abstract

Changed Host Display Information (HDI) may be captured, selectively encoded, and optionally transmitted between participants over a session. Hints indicative of which portions of the HDI may have changed are collected and used to select areas of HDI for processing. Changed HDI is encoded using an encoding process selected from a number of encoding processes by determining which process is likely to efficiently encode that portion of the HDI. Where the HDI is divided into tiles for processing the encoding method selection may take place on a tile-by-tile basis, for example by counting the number of colors in the tile to be encoded. Changed HDI may be transmitted to viewers using paint commands containing pixel information and copy commands indicating that a portion of the HDI has been moved.

1 - 17 . (canceled) 
     
     
         18 . A method of selective encoding of modular portions of host display information, the method comprising the steps of:
 processing, by a host computer, a modular portion of host display information to determine if it has changed relative to an earlier version of the modular portion of the host display information; and   if the modular portion has changed relative to the earlier version,
 counting, by the host computer, a number of colors represented in the modular portion of the host display information; 
 selecting, by the host computer, an encoding method for that modular portion of host display information according to the number of colors represented in the modular portion of the host display information, the encoding method being selected from a solid color encoding process, a JPEG encoding process, and a ZLIB encoding process; and 
 encoding, by the host computer, the modular portion using the selected encoding method. 
   
     
     
         19 . (canceled)