2.11 Generating multiview stereo images
Taking a sequence of photos for making a lenticular stereo image requires special conditions: a still object, a tripod for the camera and the same lighting during the whole photography session. Besides, photos often need to be corrected – askew images, shifted frames (these operations can be fulfilled in Legend or Photoshop). If you follow all these rules, you will get a perfect stereo photo as a result.
However, for creating collages, imposing photo objects on pictures or performing professional design work, there is a special method that allows you to create stereo pieces from a set of “flat” layers – the method of multilayer stereo generation.
A multilayer stereo image (the so called, "pseudo-image") is an encoded sequence of source frames obtained through setting non-zero parallax for one or more photo layers. By layers we mean photographs, frames imposed on them, and other photo objects.
The distance to objects (layers) of the multilayer stereo image is determined by parallax values. The object “in focus”, i.e. perceived by both eyes equally, without displacement, is an object with zero parallax. Distances to all other objects in the background or foreground will be evaluated in respect to this object.
Legend allows you to prepare a sequence of frames from a set of layers with transparency and then encode it, i.e. getting a multilayer stereo photograph. The final image will have layers located at a different distance from each other, which would provide the stereo effect.
Sequence of steps when creating a multilayer stereo image:
- Create a new project or open an existing one;
- Add files with layers to the project;
- Arrange layers in the necessary order on the canvas;
- Set the background and foreground parallax values;
- Arrange layers according to their depth using the depth scale;
- Run the menu command to generate the frame sequence:
Layers >> Generate multiview (Alt+G), the dialog will appear where you should choose the automatic or manual mode for frame number (N) calculation. For the automatic N calculation you need to set (choose) the printer resolution (ppi) and lens pitch (lpi);
- Use the Project >> Export frames menu command to save the generated series of frames;
- After that you can follow the procedure described in the previous sections - to encode images of any type: lenticular, anaglyph, etc.
Please, see section 4.2 for a step-by-step guide on creating multiview stereo photographs.