3D notion isn’t new in the modern world. Coming from 3D movies, now this prefix is used almost everywhere. We are not longer surprised with such items as 3D glasses, 3D printer, 3D website, 3D puzzle, and even 3D nails and tattoo! I won’t go into the insights of 3D objects variety, but rather stay on 3D video concept and will try to demystify the so-called 3D video converters. Do they really exist and provide the true 3D stereo? Let’s figure out.
What is True 3D?
Stereoscopic 3D, also known as “True 3D”, is a technique for adding the illusion of depth to a two-dimensional or “flat”, visual media. The stereoscopic method presents two offset 2D images for the left and right eyes of the viewer, which are then combined in the brain to give the perception of 3D depth.
How 3D video is made?
To shoot a stereo 3D, two video cameras must be used. Theoretically, everyone can try do this by simple positioning two camcorders next to each other and then combining the output videos together with 3D YouTube editor, for example. However, true 3D isn’t limited to the use of physical video recorders for live action media. In practice, real systems used in production are much more powerful, such as the Fusion 3D system developed by James Cameron for Avatar.
How 3D is displayed?
The left and right view of a stereoscopic video can be stored using different layouts. Sometimes the two views are stored as two separate video streams, but most often both views are packed into a single video stream and need to be unpacked by the video player. The most common types of 3D video display are:
- anaglyph: the oldest 3D display format which uses screens of different (usually red and cyan) colours to each eye to create a 3D image;
- side-by-side: streams for each eye are placed left-right;
- top-bottom: the same as the previous one, but streams are placed top-bottom;
- interleaved: video streams are shown in one and the same display in vertical or horizontal rows.
Find 3D videos on YouTube, you’ll be offered the same 3D viewing options. Choose the appropriate one depending on 3D glasses that you have.
What do 3D video converters do?
There is an ongoing demand for “3D video converter” in Google. People want to convert either 2D to 3D, 3D to 2D, or between different 3D formats. Let’s see what the so-called 3D video converters can offer.
I checked the first 5 results on the query “3D video converter”. Most of the tested tools promise to convert 2D to 3D. Still you’ll never get the true 3D stereo (which should be shot with 2 cameras) on the output using such tools. What they really do is just adding the depth to flat 2D video. Some tools do this automatically, others let control 3D depth and shift, but in both cases the result leaves much to be desired :(. 2D to 3D conversion is done very roughly, so the video looks like this (put on anaglyph glasses):
As to 3D to 2D conversion, it’s also possible with some of the tested tools: they just take one video stream out of two 3D ones. This is not hard and regular video converters with manual crop option can easily do this by saving one of the screens of syde-by-side 3D video.
Conversion between different 3D video formats is a way rarer task, since modern TV sets with 3D playback option and desktop video players already support more than one 3D video display format.
Are 3D video converters real? Yes, there are some, but what they produce is pseudo-3D video, usually of poor quality.