Method and device for stereo base extension of stereoscopic images and image sequences
The invention relates to a method and a device for improving the depth impression of stereoscopic images and image sequences. In autostereoscopic multi-viewer display devices, generally a plurality of intermediate perspectives are generated, which lead to a reduced stereo base upon perception by the viewers. The stereo base widening presented in this application leads to a significant improvement and thus to a more realistic depth impression. It can either be effected during recording in the camera or be integrated into a display device. The improvement in the depth impression is achieved by the generation of synthetic perspectives situated, in the viewing direction of the camera lenses, on the left and right of the extreme left and extreme right recorded camera perspective on the right and left lengthening of the connection line formed by the extreme left and extreme right camera perspectives. These synthetic perspectives are calculated only on the basis of a disparity map, which is supplied or which is calculated in a preprocessing step. In this case, the method presented solves the following problems: 1. Calculation of the new extension perspectives, 2. Correct repositioning of the camera perspectives supplied within the visual zones, 3. Definition of which disparities are intended to be continued in the case of collision in the extension and 4. Interpolation of the image regions which become visible as a result of the extension of the stereo base. In this case, instances of left and right masking are also identified and optically correctly maintained and supplemented in the extension perspectives.
1. A method for the generation of M greater or equal to 2 synthetic perspectives from a fed stereo image with at least N greater or equal to 2 perspectives such that at least one perspective LE in the viewing direction of the camera is generated left of the left-most fed camera perspective, and at least one perspective RE in the viewing direction of the camera is generated right of the right-most fed camera perspective in such a way that
a disparity map Wohin from the left-most fed camera perspective LC to the right-most camera perspective RE is computed;
for each row of the fed camera perspective an array pLC and an array pRC is generated, the content of the arrays being pointers to the pixels of the left-most fed camera perspective LC and the right-most fed camera perspective;
a new disparity map LE_Wohin is computed, where an index jllExtension being computed for each pixel jll of each row and pLC(jllExtension)=jll, pRC(jllExtension)=Wohin(jll) being set; and
the synthetic perspectives LE and RE are generated using the disparity map LE_Wohin and the pointers of the arrays pLC and pRC pointing to the pixels of the fed camera perspectives LC and RC;
where both synthetic perspectives are located left and right of the extension of the connecting line between left-most and right-most fed camera perspective LC and RC.
2. The method according to claim 1 , wherein given at least one synthetic perspective, at least one pixel of the synthetic perspective(s) which does not have to be displayed on the display device is not generated.
3. The method according to claim 1 , wherein for a fed limit ε the number of synthetic perspectives is computed such that the distance between two adjacent perspectives is smaller than the limit s with respect to the distance between the left fed camera perspective LC and the right fed camera perspective RC.
4. The Method according to claim 1 , wherein an extension factor F is computed such that the resulting maximum disparity between the pixels of the left-most synthetic and right-most synthetic perspective lies between a fixed lower limit DU and a fixed upper limit DO, with
the maximum disparity Dmax being extracted from the disparity map Wohin, and
the extension factor F: =(DO+DU)/2)/Dmax is determined.
5. The Method according to claim 1 , wherein a disparity map is computed from the fed camera perspectives and a fed depth map.
6. A device for the generation of M greater or equal to 2 synthetic perspectives according to the method of claim 1 comprising at least one processing unit for the computation of the synthetic perspectives, and at least one storage unit in which the fed camera perspectives and synthetic perspectives are stored.