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; a third component defining disparity signaling information for use in overlaying image data over the respective ones of the multiple 2D images, where the third component comprises a parameter defining disparity information having a time-varying disparity profile providing a predictor for indicating how a disparity of an overlay is expected to change over time; and wherein the three-dimensional image signal comprises a further third component, at a later time in the three-dimensional image signal than the third component, defining new disparity signaling information for use in overlaying image data over the respective ones of the multiple 2D images, the further third component comprising a further parameter defining new disparity information having a new time-varying disparity profile providing a further predictor for indicating how a disparity of an overlay is expected to change over time, the new disparity signaling information in the further third component overruling the disparity signaling information in the third component. - 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; a third component defining disparity signaling information for use in overlaying image data over the respective ones of the multiple 2D images, where the third component comprises a parameter defining disparity information having a time-varying disparity profile providing a predictor for indicating how a disparity of an overlay is expected to change over time; and wherein the three-dimensional image signal comprises a further third component, at a later time in the three-dimensional image signal than the third component, defining new disparity signaling information for use in overlaying image data over the respective ones of the multiple 2D images, the further third component comprising a further parameter defining new disparity information having a new time-varying disparity profile providing a further predictor for indicating how a disparity of an overlay is expected to change over time, the new disparity signaling information in the further third component overruling the disparity signaling information in the third component. a first component comprising multiple 2D images for use in stereoscopic viewing; a second component comprising overlay data; a third component defining disparity signaling information for use in overlaying image data over the respective ones of the multiple 2D images, where the third component comprises a parameter defining disparity information having a time-varying disparity profile providing a predictor for indicating how a disparity of an overlay is expected to change over time; and wherein the three-dimensional image signal comprises a further third component, at a later time in the three-dimensional image signal than the third component, defining new disparity signaling information for use in overlaying image data over the respective ones of the multiple 2D images, the further third component comprising a further parameter defining new disparity information having a new time-varying disparity profile providing a further predictor for indicating how a disparity of an overlay is expected to change over time, the new disparity signaling information in the further third component overruling the disparity signaling information in the third component.