A computer-implemented method comprising: displaying an image of a shared work product at a display; receiving from a video camera an image of the display and a region around that display, the region comprising an object between the display and the video camera, the shared work product being shared over a communications network by at least a first user local to the display and a second user remote of the first user; segmenting the received image to obtain a background region corresponding to the display and a foreground region corresponding to the object between the display and the video camera; estimating, from the received image, a relative depth of the object between the display and the video camera from the display; composing an output image to be presented at a remote display associated with the second user by combining an image of the shared work product and the foreground region corresponding to the object between the display and the video camera using either: a weighting related to the estimated relative depth; or with transparency or blur applied wherein the amount of transparency or blur applied is proportional to the estimated relative depth; such that an image of the object between the display and the video camera is made sharper and opaque when the object between the display and the video camera is close to the display and blurred and transparent when the object between the display and the video camera is far from the display so as to provide an advance information about a user action of the first user; and using the output image to facilitate collaboration between the users on the shared work product. displaying an image of a shared work product at a display; receiving from a video camera an image of the display and a region around that display, the region comprising an object between the display and the video camera, the shared work product being shared over a communications network by at least a first user local to the display and a second user remote of the first user; segmenting the received image to obtain a background region corresponding to the display and a foreground region corresponding to the object between the display and the video camera; estimating, from the received image, a relative depth of the object between the display and the video camera from the display; composing an output image to be presented at a remote display associated with the second user by combining an image of the shared work product and the foreground region corresponding to the object between the display and the video camera using either: a weighting related to the estimated relative depth; or with transparency or blur applied wherein the amount of transparency or blur applied is proportional to the estimated relative depth; a weighting related to the estimated relative depth; or with transparency or blur applied wherein the amount of transparency or blur applied is proportional to the estimated relative depth; such that an image of the object between the display and the video camera is made sharper and opaque when the object between the display and the video camera is close to the display and blurred and transparent when the object between the display and the video camera is far from the display so as to provide an advance information about a user action of the first user; and using the output image to facilitate collaboration between the users on the shared work product.