A New Method for Absolute Pose Estimation with Unknown Focal Length and Radial Distortion

Area of Science:

• Computer Vision
• Robotics
• Photogrammetry

Background:

• Accurate camera pose estimation is crucial for many computer vision tasks.
• Wide-angle or zoom lenses often introduce unknown focal length and radial distortion, complicating pose estimation.
• Existing methods may struggle with simultaneous estimation of pose, focal length, and distortion.

Purpose of the Study:

• To propose an efficient and robust method for single-solution absolute camera pose estimation.
• To address scenarios with unknown focal length and radial distortion.
• To provide a method applicable to various distortion models.

Main Methods:

• Decomposition of the problem into two sub-problems: focal length/radial distortion estimation and absolute pose determination.
• Utilizing the geometric characteristic that radial distortion preserves the orientation of image points relative to the distortion center.
• Employing geometric linear constraints for pose estimation after obtaining an undistorted image.

Main Results:

• Accurate estimation of focal length and up to fourth-order radial distortion.
• Efficient and accurate determination of absolute camera pose.
• Demonstrated accuracy and numerical stability on synthetic and real image data.

Conclusions:

• The proposed method effectively estimates absolute camera pose with unknown focal length and radial distortion.
• The decomposition strategy simplifies and enhances the efficiency of the estimation process.
• The method shows promise for real-world applications requiring precise camera localization.