Merge pull request #25028 from asmorkalov:as/fisheye_solvepnp

solvePnP implementation for Fisheye camera model #25028

Credits to Linfei Pan
Extracted from https://github.com/opencv/opencv/pull/24052

**Warning:** The patch changes Obj-C generator behaviour and adds "fisheye_" prefix for all ObjC functions from namespace.

### Pull Request Readiness Checklist

See details at https://github.com/opencv/opencv/wiki/How_to_contribute#making-a-good-pull-request

- [x] I agree to contribute to the project under Apache 2 License.
- [x] To the best of my knowledge, the proposed patch is not based on a code under GPL or another license that is incompatible with OpenCV
- [x] The PR is proposed to the proper branch
- [x] There is a reference to the original bug report and related work
- [ ] There is accuracy test, performance test and test data in opencv_extra repository, if applicable
      Patch to opencv_extra has the same branch name.
- [ ] The feature is well documented and sample code can be built with the project CMake

Co-authored-by: lpanaf <linpan@student.ethz.ch>
Co-authored-by: Vadim Levin <vadim.levin@xperience.ai>

modules/calib3d/include/opencv2/calib3d.hpp

@@ -4055,6 +4055,45 @@ optimization. It is the \f$max(width,height)/\pi\f$ or the provided \f$f_x\f$, \
                                   OutputArray R, OutputArray T, int flags = fisheye::CALIB_FIX_INTRINSIC,
                                   TermCriteria criteria = TermCriteria(TermCriteria::COUNT + TermCriteria::EPS, 100, DBL_EPSILON));
 
+    /**
+    @brief Finds an object pose from 3D-2D point correspondences for fisheye camera moodel.
+
+    @param objectPoints Array of object points in the object coordinate space, Nx3 1-channel or
+    1xN/Nx1 3-channel, where N is the number of points. vector\<Point3d\> can be also passed here.
+    @param imagePoints Array of corresponding image points, Nx2 1-channel or 1xN/Nx1 2-channel,
+    where N is the number of points. vector\<Point2d\> can be also passed here.
+    @param cameraMatrix Input camera intrinsic matrix \f$\cameramatrix{A}\f$ .
+    @param distCoeffs Input vector of distortion coefficients (4x1/1x4).
+    @param rvec Output rotation vector (see @ref Rodrigues ) that, together with tvec, brings points from
+    the model coordinate system to the camera coordinate system.
+    @param tvec Output translation vector.
+    @param useExtrinsicGuess Parameter used for #SOLVEPNP_ITERATIVE. If true (1), the function uses
+    the provided rvec and tvec values as initial approximations of the rotation and translation
+    vectors, respectively, and further optimizes them.
+    @param flags Method for solving a PnP problem: see @ref calib3d_solvePnP_flags
+    This function returns the rotation and the translation vectors that transform a 3D point expressed in the object
+    coordinate frame to the camera coordinate frame, using different methods:
+    - P3P methods (@ref SOLVEPNP_P3P, @ref SOLVEPNP_AP3P): need 4 input points to return a unique solution.
+    - @ref SOLVEPNP_IPPE Input points must be >= 4 and object points must be coplanar.
+    - @ref SOLVEPNP_IPPE_SQUARE Special case suitable for marker pose estimation.
+    Number of input points must be 4. Object points must be defined in the following order:
+    - point 0: [-squareLength / 2,  squareLength / 2, 0]
+    - point 1: [ squareLength / 2,  squareLength / 2, 0]
+    - point 2: [ squareLength / 2, -squareLength / 2, 0]
+    - point 3: [-squareLength / 2, -squareLength / 2, 0]
+    - for all the other flags, number of input points must be >= 4 and object points can be in any configuration.
+    @param criteria Termination criteria for internal undistortPoints call.
+    The function interally undistorts points with @ref undistortPoints and call @ref cv::solvePnP,
+    thus the input are very similar. Check there and Perspective-n-Points is described in @ref calib3d_solvePnP
+    for more information.
+    */
+    CV_EXPORTS_W bool solvePnP( InputArray objectPoints, InputArray imagePoints,
+                                InputArray cameraMatrix, InputArray distCoeffs,
+                                OutputArray rvec, OutputArray tvec,
+                                bool useExtrinsicGuess = false, int flags = SOLVEPNP_ITERATIVE,
+                                TermCriteria criteria = TermCriteria(TermCriteria::MAX_ITER + TermCriteria::EPS, 10, 1e-8)
+                              );
+
 //! @} calib3d_fisheye
 } // end namespace fisheye