An image encoding method that allows stereoscopic rendering basically comprises the following steps. In a primary encoding step (VDE1), a visual image is encoded in accordance with a standard. In an auxiliary encoding step (GRE), stereo-enabling data that is associated with the visual image is encoded as if the stereo-enabling data was an auxiliary image that can be combined with the visual image in accordance with the standard concerned. The stereo-enabling data comprises respective values that indicate respective distances between respective areas in the visual image and a virtual observer. In a composition definition step (CTR1), a composition definition is provided that causes a decoding device, which operates in accordance with the standard, to include the stereo-enabling data as a graphics image in at least one specific area of an output image, which can be transmitted to a display device.