Video encoding device, video encoding method, video reproducing device, video reproducing method, video recording medium, and video data stream
In a system for visualizing a stereoscopic image by displaying separate video images for the left and right eyes, sub-picture data (GRD) is created for the left eye and displayed superimposed on left-eye video data (VDD) as a left-eye sub-picture without change. The right-eye sub-picture ( 106 ) is displayed by shifting the horizontal positions at which the sub-picture data created for the left eye is displayed by prescribed widths. For example, the sub picture may include a plurality of objects (GRD- 1 , GRD- 2 , . . . , GRD-N); shift widths ( 108, 110 ) of the horizontal positions of the left and right ends of the objects are individually set and stored in the sub-picture data for displaying the objects for the right eye. A sub-picture superimposed on a stereoscopic video image can thereby be rendered in the depth direction, and the data size of the sub-picture and the amount of computation required for its display can be reduced.
1. A video encoding device that generates video data for visualization of a stereoscopic video image by display of separate video images for the left and right eyes, the video encoding device comprising:
a sub-video encoding unit configured to encode data of monoscopic sub-video display images for first and second viewpoints to be displayed superimposed on main video display images for the first and second viewpoints forming the stereoscopic video image, the sub-video display images for the first and second viewpoints displayed as additional video data of the main video display images, thereby generating an encoded sub-video data stream; wherein
the sub-video encoding unit encodes the data of one or more objects included in the sub-video display image for the first viewpoint so that the data can be independently decoded and displayed, and
the sub-video encoding unit dependently encodes the second viewpoint with respect to the first viewpoint by only encoding depth expressions determined by performing at least an expansion or contraction, in a horizontal direction, of one or more objects included in the sub-video display image for the second viewpoint with respect to corresponding objects included in the sub-video display image for the first viewpoint thereby changing the shape of said one or more objects and the perspective view of said second viewpoint.
2. The video encoding device of claim 1 , wherein data indicating a shift width at the left end and a shift width at the right end in the horizontal direction on the display surface, for each of the objects, are generated independently as the data of sub-video display image for the second viewpoint.
3. A video reproducing device that decodes data of a stereoscopic video image including a sub-video image encoded by the video encoding device of claim 1 , and displays separate video images for the left and right eyes, thereby visualizing the stereoscopic video image, the video reproducing device comprising:
a sub-video decoding unit configured to decode data of monoscopic sub-video display images for a plurality of viewpoints, the sub-video display images being displayed superimposed on main video display images for the first and second viewpoints forming the stereoscopic video image, the sub-video display images for the plurality of viewpoints being displayed as additional video data for the main video display images; wherein the sub-video decoding unit
independently decodes the data of one or more objects included in the sub-video display image for the first viewpoint, and
dependently decodes the data of one or more objects included in the sub-video display image for the second viewpoint by decoding depth expressions and performing at least an expansion or contraction, in the horizontal direction on the display surface, of one or more objects included in the sub-video display image for the second viewpoint with respect to corresponding objects included in the sub-video display image for the first viewpoint, based on the depth expression data of the sub-video display image for the second viewpoint, and displays the result.
4. A non-transitory video recording medium storing data of a sub-video image encoded by the video encoding device of claim 1 , being multiplexed with the data of the stereoscopic video image.
5. A video encoding method that generates video data for visualization of a stereoscopic video image by display of separate video images for the left and right eyes, the video encoding method comprising:
a sub-video encoding step for encoding data of monoscopic sub-video display images for first and second viewpoints to be displayed superimposed on main video display images for the first and second viewpoints forming the stereoscopic video image, the sub-video display images for the first and second viewpoints being displayed as additional video data for the main video display images, thereby generating an encoded sub-video data stream; wherein the sub-video encoding step includes:
a substep of encoding the data of one or more objects included in the sub-video display image for the first viewpoint so that the data can be independently decoded and displayed, and
a substep of encoding the data of one or more objects included in the sub-video display image for the second viewpoint so that the data dependently decoded with respect to the first viewpoint and displayed by only encoding depth expressions determined by performing at least an expansion or contraction, in a horizontal direction, of one or more objects included in the sub-video display image for the second viewpoint with respect to corresponding objects included in the sub-video display image for the first viewpoint thereby changing the shape of said one or more objects and the perspective view of said second viewpoint, depth being expressed by these sub-steps.
6. The video encoding method of claim 5 , wherein data indicating a shift width at the left end and a shift width at the right end in the horizontal direction on the display surface, for each of the objects, are generated independently as the data of the subvideo display image for the second viewpoint.
7. A video reproducing method that decodes data of a stereoscopic video image including a sub-video image encoded by the video encoding method of claim 5 , and displays separate video images for the left and right eyes, thereby visualizing the stereoscopic video image, the video reproducing method comprising:
a sub-video decoding step for decoding data of monoscopic sub-video display images for a plurality of viewpoints, the sub-video display images being displayed superimposed on main video display images for the first and second viewpoints forming the stereoscopic video image, the sub-video display images for the plurality of viewpoints being displayed as additional video data for the main video display images; wherein the sub-video decoding step includes:
a substep of independently decoding the data of one or more objects included in the sub-video display image for the first viewpoint, and
a substep of dependently decoding the data of one or more objects included in the sub-video display image for the second viewpoint by decoding depth expressions and performing at least an expansion or contraction, in the horizontal direction on the display surface, of one or more objects included in the sub-video display image for the second viewpoint with respect to corresponding objects included in the sub-video display image for the first viewpoint based on the depth expression data of the sub-video display image for the second viewpoint, and displaying the result.