Stereo vision is an important branch of the research area in computer vision. Among the techniques of stereo vision, binocular stereo vision which is based on processing two images remains a research hotspot. Binocular stereo vision directly simulates the manner of human eyes observing one scene from two different viewpoints. By using the principle of triangulation, the disparities of a number of 3D points mapped to pixels in two images are computed. Then the visual information of depth is also recovered. The object surface shape can be acquired using these disparities. In this project, a pair of common web cameras is used to collect images. Based on OpenCV, the calibration algorithm of stereo vision is achieved. Stereo rectify and stereo matching algorithm are also rapidly and efficiently implemented. Finally, the depth information of object is obtained.
Figure 1 will show you about concept of stereo camera to get deep. But some parameter must get from calibraion, In our experiment, we used a pair of common network cameras which are of the same type. Both of them are fixed to make sure that they are well rowaligned and have very short base line as well. Chessboard is used as the standard calibration object which has 7x6 grids with the interval of 2 cm. The chessboard was placed in the region in which both of the two cameras can capture the overall view of it. The pose of chessboard was then changed and 40 pairs of images are captured by cameras. Each pair of images is captured at the same time. Figure 2 shows an example of such pairs.
Figure 1. The concept of stereo camera to get deep.
- Z are the coordinates of a 3D point in the world coordinate space
- C1,C2 is a principal point that is usually at the image center
- f are the focal lengths expressed in pixel units.
Figure 2. Chessboard calibration
For more detail about stereo camera and calibration you can download my paper in button below.
Untuk penjelasan lebih detail mengenai stereo image dapat anda download dan baca paper yang telah saya buat dibawah ini.
And you can download my full source code about stereo camera and you can directly from button below. My program run in Visual Studio 2013 if you haven't yet you can download the software . for library I use OpenCV 2.4.13 anda you can download HERE. But I would like to advice you to study Segmentation using Threshold HSV firstly before this project in HERE.
My Video Project.