VNC tight encoder-data compression for VNC

VNC (Virtual Network Computing) (Richardson et al., 1998) is a multi-platform software suite allowing users to access graphic displays remotely via TCP/IP network. It is based on the client/server architecture and uses RFB (Remote FrameBuffer) protocol for actual data exchange. The client software runs on the local user´s machine while the server part operates at the target host. This way VNC brings remote display to the local user´s machine and allows the user to control the target computer with his local keyboard and mouse or other pointing device. The RFB protocol is based on the FrameBuffer paradigm, where a display is represented by a rectangular array of color samples denoting separate image pixels. The server maintains the original screen contents, monitors its changes, and periodically sends changed parts to connected clients upon their explicit requests. This report describes and analyses the VNC Tight Encoding, new encoding scheme for VNC aimed to minimize both compressed size of pixel data and compression speed in terms of server-side CPU load