If the screen image is directly transmitted in bitmap
format, it may cause control delay which is relatively large.
In order to improve the transmissions' efficiency, we
compress the data before it was transmitted to increase the
control of data transmission. In addition, we also can use the
screen image’s transmission delay’s file format to improve
the rate, it reduces the control delay by compressing the
screen image which were directly transmitted into data
stream. Taking account of the maximum UDP protocol’s
packet length is 64KB, and the compressed screen image
data exceed 64KB, since the compression ratio can’t too be
large, we use TCP protocol to transfer the screens’ image
data.