Fisheye / equadistant model pinhole camera model class. More...
#include <CamEqui.h>
Public Member Functions | |
| CamEqui (int width, int height) | |
| Default constructor. More... | |
| void | compute_distort_jacobian (const Eigen::Vector2d &uv_norm, Eigen::MatrixXd &H_dz_dzn, Eigen::MatrixXd &H_dz_dzeta) override |
| Computes the derivative of raw distorted to normalized coordinate. More... | |
| Eigen::Vector2f | distort_f (const Eigen::Vector2f &uv_norm) override |
| Given a normalized uv coordinate this will distort it to the raw image plane. More... | |
| Eigen::Vector2f | undistort_f (const Eigen::Vector2f &uv_dist) override |
| Given a raw uv point, this will undistort it based on the camera matrices into normalized camera coords. More... | |
| ~CamEqui () | |
 Public Member Functions inherited from ov_core::CamBase | |
| CamBase (int width, int height) | |
| Default constructor. More... | |
| cv::Point2f | distort_cv (const cv::Point2f &uv_norm) |
| Given a normalized uv coordinate this will distort it to the raw image plane. More... | |
| Eigen::Vector2d | distort_d (const Eigen::Vector2d &uv_norm) |
| Given a normalized uv coordinate this will distort it to the raw image plane. More... | |
| cv::Vec4d | get_D () |
| Gets the camera distortion. More... | |
| cv::Matx33d | get_K () |
| Gets the camera matrix. More... | |
| Eigen::MatrixXd | get_value () |
| Gets the complete intrinsic vector. More... | |
| int | h () |
| Gets the height of the camera images. More... | |
| virtual void | set_value (const Eigen::MatrixXd &calib) |
| This will set and update the camera calibration values. This should be called on startup for each camera and after update! More... | |
| cv::Point2f | undistort_cv (const cv::Point2f &uv_dist) |
| Given a raw uv point, this will undistort it based on the camera matrices into normalized camera coords. More... | |
| Eigen::Vector2d | undistort_d (const Eigen::Vector2d &uv_dist) |
| Given a raw uv point, this will undistort it based on the camera matrices into normalized camera coords. More... | |
| int | w () |
| Gets the width of the camera images. More... | |
| virtual | ~CamBase () |
Additional Inherited Members | |
| Protected Member Functions inherited from ov_core::CamBase | |
| CamBase ()=default | |
| Protected Attributes inherited from ov_core::CamBase | |
| int | _height |
| Height of the camera (raw pixels) More... | |
| int | _width |
| Width of the camera (raw pixels) More... | |
| cv::Vec4d | camera_d_OPENCV |
| Camera distortion in OpenCV format. More... | |
| cv::Matx33d | camera_k_OPENCV |
| Camera intrinsics in OpenCV format. More... | |
| Eigen::MatrixXd | camera_values |
| Raw set of camera intrinic values (f_x & f_y & c_x & c_y & k_1 & k_2 & k_3 & k_4) More... | |
Detailed Description
Fisheye / equadistant model pinhole camera model class.
As fisheye or wide-angle lenses are widely used in practice, we here provide mathematical derivations of such distortion model as in OpenCV fisheye.
![\begin{align*} \begin{bmatrix} u \\ v \end{bmatrix}:= \mathbf{z}_k &= \mathbf h_d(\mathbf{z}_{n,k}, ~\boldsymbol\zeta) = \begin{bmatrix} f_x * x + c_x \\ f_y * y + c_y \end{bmatrix}\\[1em] \empty {\rm where}~~ x &= \frac{x_n}{r} * \theta_d \\ y &= \frac{y_n}{r} * \theta_d \\ \theta_d &= \theta (1 + k_1 \theta^2 + k_2 \theta^4 + k_3 \theta^6 + k_4 \theta^8) \\ \quad r^2 &= x_n^2 + y_n^2 \\ \theta &= atan(r) \end{align*}](form_0.png)
where ![$ \mathbf{z}_{n,k} = [ x_n ~ y_n ]^\top$](form_1.png)
are the normalized coordinates of the 3D feature and u and v are the distorted image coordinates on the image plane. Clearly, the following distortion intrinsic parameters are used in the above model:
In analogy to the previous radial distortion (see ov_core::CamRadtan) case, the following Jacobian for these parameters is needed for intrinsic calibration:
![\begin{align*} \frac{\partial \mathbf h_d (\cdot)}{\partial \boldsymbol\zeta} = \begin{bmatrix} x_n & 0 & 1 & 0 & f_x*(\frac{x_n}{r}\theta^3) & f_x*(\frac{x_n}{r}\theta^5) & f_x*(\frac{x_n}{r}\theta^7) & f_x*(\frac{x_n}{r}\theta^9) \\[5pt] 0 & y_n & 0 & 1 & f_y*(\frac{y_n}{r}\theta^3) & f_y*(\frac{y_n}{r}\theta^5) & f_y*(\frac{y_n}{r}\theta^7) & f_y*(\frac{y_n}{r}\theta^9) \end{bmatrix} \end{align*}](form_3.png)
Similarly, with the chain rule of differentiation, we can compute the following Jacobian with respect to the normalized coordinates:
![\begin{align*} \frac{\partial \mathbf h_d(\cdot)}{\partial \mathbf{z}_{n,k}} &= \frac{\partial uv}{\partial xy}\frac{\partial xy}{\partial x_ny_n}+ \frac{\partial uv}{\partial xy}\frac{\partial xy}{\partial r}\frac{\partial r}{\partial x_ny_n}+ \frac{\partial uv}{\partial xy}\frac{\partial xy}{\partial \theta_d}\frac{\partial \theta_d}{\partial \theta}\frac{\partial \theta}{\partial r}\frac{\partial r}{\partial x_ny_n} \\[1em] \empty {\rm where}~~~~ \frac{\partial uv}{\partial xy} &= \begin{bmatrix} f_x & 0 \\ 0 & f_y \end{bmatrix} \\ \empty \frac{\partial xy}{\partial x_ny_n} &= \begin{bmatrix} \theta_d/r & 0 \\ 0 & \theta_d/r \end{bmatrix} \\ \empty \frac{\partial xy}{\partial r} &= \begin{bmatrix} -\frac{x_n}{r^2}\theta_d \\ -\frac{y_n}{r^2}\theta_d \end{bmatrix} \\ \empty \frac{\partial r}{\partial x_ny_n} &= \begin{bmatrix} \frac{x_n}{r} & \frac{y_n}{r} \end{bmatrix} \\ \empty \frac{\partial xy}{\partial \theta_d} &= \begin{bmatrix} \frac{x_n}{r} \\ \frac{y_n}{r} \end{bmatrix} \\ \empty \frac{\partial \theta_d}{\partial \theta} &= \begin{bmatrix} 1 + 3k_1 \theta^2 + 5k_2 \theta^4 + 7k_3 \theta^6 + 9k_4 \theta^8\end{bmatrix} \\ \empty \frac{\partial \theta}{\partial r} &= \begin{bmatrix} \frac{1}{r^2+1} \end{bmatrix} \end{align*}](form_4.png)
To equate this to one of Kalibr's models, this is what you would use for pinhole-equi.
Constructor & Destructor Documentation
◆ CamEqui()
|
inline |
◆ ~CamEqui()
Member Function Documentation
◆ compute_distort_jacobian()
|
inlineoverridevirtual |
Computes the derivative of raw distorted to normalized coordinate.
- Parameters
-
uv_norm Normalized coordinates we wish to distort H_dz_dzn Derivative of measurement z in respect to normalized H_dz_dzeta Derivative of measurement z in respect to intrinic parameters
Implements ov_core::CamBase.
◆ distort_f()
|
inlineoverridevirtual |
Given a normalized uv coordinate this will distort it to the raw image plane.
- Parameters
-
uv_norm Normalized coordinates we wish to distort
- Returns
- 2d vector of raw uv coordinate
Implements ov_core::CamBase.
◆ undistort_f()
|
inlineoverridevirtual |
Given a raw uv point, this will undistort it based on the camera matrices into normalized camera coords.
- Parameters
-
uv_dist Raw uv coordinate we wish to undistort
- Returns
- 2d vector of normalized coordinates
Implements ov_core::CamBase.
The documentation for this class was generated from the following file: