A 3D source device for outputting a three-dimensional image signal, the three-dimensional image signal comprising multi-view image data, the 3D source device comprising an input for receiving image data; a generator arranged to generate the three-dimensional image signal based on the image data, the three-dimensional image signal comprising a first component comprising multiple 2D images for use in stereoscopic viewing, a second component comprising overlay data and a third component defining disparity signaling information for use in overlaying image data over the respective ones of the multiple 2D images. New disparity signaling information in a further third component overrules the disparity signaling information in the third component.