Rendering Active Speaker Image at Higher Resolution than Non-active Speakers at a Video Conference Terminal

A collaborative working environment is established between a plurality of client units. Each client unit is operable to collect a video input and to generate a scalable video signal therefrom for use in others of the client units. The client units are each configured to display images generated at one or more of the other client units, and at least one of the client units is operable to display images from two or more of the client units. An active participant is determined (e.g. using participant identification information), corresponding to one of said client units, and, at a client unit displaying more than one participant image, the image corresponding to the active participant is rendered at a high resolution (PARTICIPANT 2) while the or each other participant image is rendered at a lower resolution (PARTICIPANT 3). Each client unit may comprise first and second rendering means to render the first and second resolution images.