I’ve introduced the free Gimpel3D manual 2D to 3D stereo conversion software here on the blog back in 2011, and now the author has made it an open source software by releasing the code of the project on Sourceforge. Gimpel3D is a free application that can help you convert a single 2D image or image sequence into stereoscopic 3D written by René Gimpel. The conversion to 3D is manual and the software only assists you, so do not expect automation like with an 2D to 3D autoconversion solutions that do everything with just a click of a button, with Gimpel3D however you can get much better results.
Since the original freeware release of Gimpel3D, many of the ideas presented in the software have become standard features in commercial software and as a result the author of the program has decided that there is no significant advantage to continue developing it as a stand-alone proprietary solution, although the codebase makes a nice platform for future research and experimentation. René Gimpel has released all source code for G3D under the GPL so that other stereo researchers, hobbyists, and/or professionals can build upon his existing work, and integrate/test new capabilities using the projective modeling environment.
Gimpel3D is a free application that can help you convert a single 2D image or image sequence into stereoscopic 3D written by René Gimpel. Have in mind that this is not like the traditional 2D to 3D autoconversion solutions that do everything by themselves, you have to do a lot of things manually to make it work, but the end result can be much more convincing than that of an automatic conversion software. Gimpel3D uses a combination of traditional approaches as well as a proprietary projective modeling system that is used to actually remodel the 2D image into a something that resembles a true 3D scene that can be rendered into a realistically looking stereoscopic 3D image. The user works in true proportional space where the scene can be viewed from any location and the scene is edited geometrically in space using tools specifically designed to work with the perspective projection of the image. So in order to be able to work with this software, some previous experience with 3D modeling and animation software packages may be of great help. And if you are totally new into stereo 3D, then this software may be quite hard to understand and use, so you better start with something more automated.
Here is one interesting video tutorial that I stumbled across that demonstrates a simple, but effective technique to create a depth map of a 2D photo or another image and then use the depth map to convert it to stereoscopic 3D image in a Side by Side format. This is done with the help of the Displace filter available in Photoshop that allows you to reconstruct the view for the other eye based on the depth map you’ve created. You should have patience and not get discouraged if you don’t manage to get great results the first time you do this, try again and again and further improve the results, but be ready to spent a lot of time experimenting. This is needed because the 2D to 3D conversion process needs not only to rely on doing the things lets say mathematically correct, but also in a way that they will visually look best and that requires visual checking. You should also be careful not to have depth contradicting cues when you are doing the conversions as this might disturb you when you view the final image and create a negative effect instead of positive one in the viewer. And in order to start making really good conversions you’ll need some time to play and experiment to get the right feeling of doing the conversion, and you’ll also get some useful experience in the process, even though in the demo video above the procedure might seem very simple and easy to you, it is not so easy getting really good results…
But let me do some more explanations about the depth maps if you don’t know what are these. Depth maps are grayscale graphic files that define the depth of each pixel of the image, so when you combine a 2D still image with a depth map file you can generate a second view of the image with the needed offset as defined in the depth map so that the result is a stereoscopic 3D image. In a depth map file the pixels rage from pure white to complete black (no other colors are being used), where if a pixel is brighter it represents the fact that the real pixel of the image should seem closer and if it is darker it should be far from the viewer. So a pixel with white color in the depth map seems close to you (jumping out of the screen), a gray one will be in between (at screen depth) and a completely black one will be furthest away from you (going inside the screen).
When converting a single 2D image into a stereoscopic 3D one with Photoshop, you need to start with drawing the depth map (in a separate layer of course) and starting with a gradient or fully filling with a grayscale color the whole image surface. This is needed in order to not have empty regions in the depth map left by mistake as this might mess up with the end result you’ll get in terms of depth. After you’ve prepared the background of the depth map, you can start to define one or more layers of depth for the different objects displayed on the image. Using additional layers for the depth map might be good idea in order to have more control when working with fine details and/or if you need to more easily convert multiple similar images. If you create more layers of depth it also means that you’ll have more depth information and the depth effect will feel more natural and close to reality, but more layers need more work as even a single more complex object (a person in the photo for example) might even need 5, 10 or even more layers with depth information and that requires more time to be done precisely.