Optimal resilience to errors in packetized streaming 3-D wireframe animation is achieved by partitioning the stream into layers and applying unequal error correction coding to each layer independently to maintain the same overall bitrate. The present invention also relates to a plant that is useful for the process provided above. The upper tong and the lower tong may be connected to an actuation gear which may drive the tongs together and apart. Compensating values are also calculated that are functions of the amounts that when added to the components of the transformed selected background pixel make its color grey.