System for compressing bit maps to be shared and displayed in collaborative tool by client and server systems

摘要

The disclosed system updates client systems regarding changes in a shared display region on a server using compressed graphical display information. The disclosed system compares a first bit map with a second bit map to generate a difference array. The difference array includes indication of each bit in the second bit map having a different value than in the first bit map. The system then transmits the difference array to a client system if at least one bit in the second bit map is different from a corresponding bit in the first bit map. In a further aspect of the disclosed system, the system run length encodes the difference array prior to transmitting if the second bit map is different from the first bit map to generate a run length encoded difference array. The client system generates an updated bit map based on an initial bit map and the difference array. The client system displays the shared region using the updated bit map. In a further aspect of the disclosed system, the server performs loss-less compression of the run length encoded difference array if the run length encoded difference array is greater than a predetermined minimum length.