Method and apparatus for caching, compressing and transmitting video signals

A method of transmitting video signals over a Keyboard, Video, Mouse (“KVM”) network from one of a plurality of remote computers to one of a plurality of user workstations, said method comprising the steps of:

• receiving at least one video signal from a remote computer;
• digitizing said video signal;
• dividing said digitized video signal into one or more pixel blocks;
• comparing said pixel block to a previously stored pixel block;
• transmitting an instruction to one of a plurality of the user workstations if the comparing does not exceed a threshold;
• computing at least a first and second hash code for each of said pixel blocks if the comparison exceeds a threshold;
• comparing said first and second hash codes to a cache of stored hash codes;
• storing said one or more pixel blocks in a cache when said first and second hash codes are not found in the cache of stored hash codes;
• transmitting to a user workstation said pixel blocks when said first and second hash codes are not in said cache;
• and
• updating a second cache with said transmitted pixel blocks.

A keyboard, video, and mouse system for selectively controlling a plurality of remotely located computers from a plurality of local user workstations comprising:

• at least one remote computer;
• at least one user workstation;
• a transformation apparatus for compressing, analyzing and converting at least one video signal from said remote computer;
• a first and second frame buffer from said at least one remote computer;
• and a cache of stored frame buffers;
• wherein said transformation apparatus compares said first frame buffer to said second frame buffer by utilizing a first threshold and a second threshold stage and transmits an instruction to at least one user workstations if the comparing does not exceed a threshold;
• wherein said transformation apparatus divides said frame buffers into current blocks and generates and stores a plurality of computed codes associated with each current block if the comparing exceeds said threshold, and wherein the transformation apparatus further compares said current blocks to said cache of stored frame buffers using the stored codes and when no match of said current blocks in said frame buffers to said cache of stored frame buffers occurs, the associated blocks are transmitted to the user workstation.