Imagen3D is a a free photo editor developed from the start to enable the adjusting and editing of stereo 3D photos, supporting multiple popular formats such as Anaglyph, Side by Side, Top/Bottom, Row Interlaced and so on. The application offers most of the basic tools used by other programs for editing and photo retouching, but they have been adapted for use with stereoscopic 3D images. The program is free and works quite well, it has a portable version as well as an installer, so you can have it handy even on an USB flash drive. It is intended for use on non stereoscopic 3D capable displays and you can preview the photos you are editing using a pair of anaglyph red-cyan glasses or with the cross-eye viewing method. And you can of course export a 3D photo and then open it inside a photo viewer supporting 3D Vision for example, but you cannot run the 3D photo in stereo 3D mode with 3D Vision right from the application itself.
With this program you can do most of what you are usually doing in a normal photo editor with 2D photos, but with 3D ones instead as there are actually not that many stereo 3D photo editors available yet and doing even some of the most basic things like cropping a 3D photo can be problematic if you don’t have the right tool. Of course there are some specific things required to be done only on 3D photos and the pretty much the only drawback is the inability for direct full-screen preview on a 3D-capable solution such as 3D Vision. But Imagen3D can be quite useful in cases when you need to do some adjustments on a 3D photo, but you don’t have a 3D display at the moment, you just need to have a good old pair of paper anaglyph glasses lying around and you are ready to go.