Patent ID: 8255461

Claim:
A method, comprising: sharing a display of a source device with one or more viewer devices, the display divided into a plurality of identified blocks; in response to changes in the display, determining an outer boundary of an updated region affected by the change, the updated region defining a plurality of update blocks of the identified blocks within the outer boundary; comparing an image within each update block to a previous version of the corresponding update block to determine whether the block is changed or unchanged; converting the image within unchanged update blocks to a different easily compressible image; compressing the updated region having the converted unchanged update blocks; and transmitting the compressed updated region from the source device to the one or more viewer devices, wherein the transmitted updated region is transmitted with instructions indicating converted unchanged update blocks within the transmitted update region and with instructions for the one or more viewer devices to use previous unconverted versions of the identified unchanged update blocks to replace the corresponding converted unchanged update blocks in the transmitted updated region to produce the shared display.