What is Stereovision?
Stereovision is the primary method that the human visual system uses to perceive depth. Stereovision is common to most predatory species, including man.
Abstract
What is Stereovision?
Stereovision is the primary method that the human visual system uses to perceive depth. Stereovision is common to most predatory species, including man. Most people have two eyes, and perceive depth by a mental interpretation of the world we view through those two eyes. Each eye gives a slightly different perspective on the objects viewed, and this slight difference provides depth cues to our brain. . Objects that are relatively close will shift a larger distance horizontally when viewed from one eye and then switching eyes. Objects that are relatively far away shift a smaller amount. It is only when we talk about viewing virtual worlds that things get complicated. Viewing a virtual world on a monitor gives no actual stereovision depth cues, as all objects are rendered at the surface of the monitor. This does not mean that there are no depth cues at all, though. The human brain has certain “experience” which is used to interpret even non-stereovision images. When the viewpoint of a virtual world is moved, objects in the world have a perception of depth based on viewing them from a different position. This is the same effect as stereovision, except that it is linear with respect to time and requires movement to generate the depth cues. Stereovision produces these depth cues without the need for movement, but is also enhanced when movement occurs. . Thus, stereovision as it pertains to viewing a virtual world means that you have the capability to produce two separate images, and that each eye sees only one of the two images. If this is done correctly, your mind will combine the two images in such a way that you actually have the perception of being “in” the virtual world rather than just viewing a picture of the virtual world. This adds a level of realism and immersion to games that is otherwise unattainable.
Our Project
Our project consisted of two stages:
1.Studying the theory concerning Stereovision and Stereoscopic image processing.
2.Implementation of the application.
At the first stage we have studied few basic rules about stereoscopic vision: how does the eye works?, how does a picture is received in the brain? In what way does our mind process a 3D image?
We have found few ways of how to make a stereoscopic image, and chose one of them – color separation due to simplicity and easier interface with computers programming languages.
As the second stage of our project we have made an application that receives a video stream from two cameras and makes real-time 3-D video stream.
Algorithm
In order to make a real-time 3-D video stream we have followed those steps:
1. Capture an image from each of the cameras. (We will refer them as image1 and image2).
2. Make a new image by using image1 as Red layer of the new image and image2 as the Green and Blue layers of the new image.
3. Show the new image on the screen.
4. Go to step 1.
The following diagram shows how does it work.
Software
The Project was written under the Win NT operating system.
We have programmed at Visual C++ in order to develop our application, in addition we have used Microsoft Vision SDK and ITEX PcVision SDK (comes with image capture board from Imaging Technology Inc.).
Hardware
The project system is comprised of a PC equipped with a Capture board from Imaging Technology Inc. and two Ikegami Cameras.
Acknowledgement
We would like to thank Johanan Erez our project supervisor for helping and guiding when any problem occurs.
Also we would like to thank “Ollendorff Minerva Center” which constantly supports the laboratories research projects and many of the lab’s equipment and software were purchased by the fund!