There isn’t a child who isn’t fascinated by Pixar’s Toy Story series. Though mere toys, Woody and Buzz Lightyear, even today, do not fail to capture the imagination of every tiny tot. 2D to 3D stereo conversion gave a whole new dimension to Disney’s first entirely computer animated feature, Toy Story (1995) and its sequel (1999).
2D to 3D video conversion (also called 2D to stereo 3D conversion and stereo conversion) is the process of transforming 2D (“flat”) film to 3D form, which in almost all cases is stereo, so it is the process of creating imagery for each eye from one 2D image. (Wikipedia)
The realm of 3D incorporates the third dimension of depth, which can be perceived by the human vision in the form of binocular disparity. The positioning of the human eyes affects the way in which they perceive different views of the real world. A native 3D production takes advantage of this phenomenon, by which two cameras are used, positioned next to each other, shooting at the same time to mimic each human eye. Those movies not shot in this manner cannot be made into a 3D film, which is where 2D to 3D stereo conversion emerges as savior.
The extreme advances in the field of computer animation enable a second camera view to be added, thereby giving depth and volume to each and every 2D frame. The position of the “second (virtual) camera” with respect to the first determines the degree of 3D, namely in front of screen (when an object seems to be in with the viewer), at screen (regular 2D image) and behind screen (when the objects seems to be at a distance away from the screen).
Filming in native 3D involves a large number of variables and taking into account the various parameters, this could involve incredibly expensive, bulky and complicated equipment and hardware. With hardware come human errors, which includes disparity and distortion of imagery shot by the left and right cameras, complex action sequences which can only be shot with 2D monocular cameras, color shift, etc., among others. Stereo post production is another major hiatus when compared to stereo conversion, in addition to being more expensive and time consuming.
On the other hand, in a stereo conversion, stereographers can perform as many digital “retakes” as required to perfect every angle and depth in order to maximize the quality of each sequence in a movie. “I get to set the parameters on a shot-by-shot basis”, says Bob Whitehill, stereoscopic supervisor at Pixar Animation Studios, “With cameras that are computer code and not physical objects, the 3D effect can be absolutely perfect, with no visual incongruity between what the left and right eyes see.” (www.tested.com)
With the growing need for high quality stereoscopic images, the future of 2D to 3D stereo conversion looms large.