Method of transferring of three dimensional image data, the method comprising, at a 3D source device, - processing source image data to generate a 3D display signal, the 3D display signal comprising a sequence of frames constituting the 3D image data according to a 3D video transfer format, the 3D video format comprising a video data period during which pixels of active video are transmitted and a data island period during which audio and auxiliary data are transmitted using a series of packets, the packets including an info frame packet, which video data period and data island period are according to HDMI, and - outputting the 3D display signal; and, at a 3D display device, - receiving the 3D display signal, and - processing 3D display signal for generating display control signals for rendering the 3D image data on a 3D display, the sequence of frames comprising units, the unit being a period from a vertical synchronization signal to the next vertical synchronization signal, each unit corresponding to a number of frames arranged according to a multiplexing scheme, the number of frames comprising video information intended to be composited and displayed as a 3D image; - each frame in the unit having a data structure for representing a sequence of digital image pixel data, and each frame representing a partial 3D data structure, and wherein the method comprises, at the 3D source device, - including 3D transfer information in the info frame packet, the 3D transfer information comprising at least information about the multiplexing scheme including the number of video frames in a unit to be composed into a single 3D image in the 3D display signal, the multiplexing scheme being selected of group of multiplexing schemes comprising at least frame alternating multiplexing, the frame alternating indicating said number of frames being sequentially arranged within said video data period; and the number of frames intended to be composited and displayed as a 3D image for at least one multiplexing scheme comprising at least one frame of graphics information; and - said generating the display control signals is performed in dependence on the 3D transfer information. - processing source image data to generate a 3D display signal, the 3D display signal comprising a sequence of frames constituting the 3D image data according to a 3D video transfer format, the 3D video format comprising a video data period during which pixels of active video are transmitted and a data island period during which audio and auxiliary data are transmitted using a series of packets, the packets including an info frame packet, which video data period and data island period are according to HDMI, and - outputting the 3D display signal; - receiving the 3D display signal, and - processing 3D display signal for generating display control signals for rendering the 3D image data on a 3D display, - each frame in the unit having a data structure for representing a sequence of digital image pixel data, and each frame representing a partial 3D data structure, and wherein the method comprises, at the 3D source device, - including 3D transfer information in the info frame packet, the 3D transfer information comprising at least information about the multiplexing scheme including the number of video frames in a unit to be composed into a single 3D image in the 3D display signal, the multiplexing scheme being selected of group of multiplexing schemes comprising at least frame alternating multiplexing, the frame alternating indicating said number of frames being sequentially arranged within said video data period; and - said generating the display control signals is performed in dependence on the 3D transfer information.