Color and depth (RGBD) sensors,such as the Microsoft Kinect,are used in many research areas.In the immersive group-to-group telepresence system ba sed on a cluster of RGBD sensors,the color and depth image streams are sent to a remote site over a network connection where they are used for the real -time reconstruction of the captured participants.Depth map coding plays a cru c ial role in the system that allows distributed groups of users to meet in a 3D s ha red virtual world.We develop and evaluate different schemes for the real-time c ompression of multiple depth image streams.Our analysis suggests that the hy brid lossless-lossy compression approach provides a good tradeoff between qual i ty and compression ratio.The lossless compression based on run length encoding i s u sed to preserve the information of the highest bits of the depth image pixels.T he lowest 10-bits of a depth pixel value are directly encoded in the Y channel o f a YUV image and encoded by a ×264codec.Our experiments show that the propose d method can encode and decode multiple depth image streams in less than 12ms o n average.Depending on the compression level,which can be adjusted during appl ication,we are able to achieve a compression ratio ranging from about 4∶1to 20∶1.Initial results indicate that the quality for 3D reconstructions is almost i ndistinguishable from the original for a compression ratio up to 10∶1.