Geometric camera calibration, also referred to as camera resectioning, estimates the parameters of a lens and image sensor of an image or video camera. You can use these parameters to correct for lens distortion, measure the size of an object in world units, or determine the location of the camera in the scene. These tasks are used in applications such as machine vision to detect and measure objects. They are also used in robotics, for navigation systems, and 3-D scene reconstruction.
Examples of what you can do after calibrating your camera:
Camera parameters include intrinsics, extrinsics, and distortion coefficients. To estimate the camera parameters, you need to have 3-D world points and their corresponding 2-D image points. You can get these correspondences using multiple images of a calibration pattern, such as a checkerboard. Using the correspondences, you can solve for the camera parameters. After you calibrate a camera, to evaluate the accuracy of the estimated parameters, you can:
1）Plot the relative locations of the camera and the calibration pattern
2）Calculate the reprojection errors.
3）Calculate the parameter estimation errors.
Use the Camera Calibrator to perform camera calibration and evaluate the accuracy of the estimated parameters.
The Computer Vision Toolbox™ calibration algorithm uses the camera model proposed by Jean-Yves Bouguet The model includes:
1)The pinhole camera model .
2)Lens distortion .
The pinhole camera model does not account for lens distortion because an ideal pinhole camera does not have a lens. To accurately represent a real camera, the full camera model used by the algorithm includes the radial and tangential(正切的) lens distortion.
Pinhole Camera Model
A pinhole camera is a simple camera without a lens and with a single small aperture. Light rays pass through the aperture and project an inverted image on the opposite side of the camera. Think of the virtual image plane as being in front of the camera and containing the upright image of the scene.
【评价】 virtual image plane指的是什么？