Fisheye Lens Dewarping Using Tangential Distortion Mapping
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Solution Overview
Problem
Standard fisheye lens dewarping algorithms assume linear radial distortion, which is not valid for many lenses, leading to increased computational complexity and load on GPUs, especially when correcting nonlinear radial distortion.
Innovation Solution
The method involves identifying real and ideal keypoints from calibration patterns, determining term coefficients through a mapping process, and using these coefficients to transform warped images into dewarped coordinates, applicable to all types of lenses regardless of their intrinsic qualities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If standard fisheye dewarping algorithms are used with nonlinear radial distortion, then manufacturing precision is maintained, but device complexity and computational load increase significantly
Solution Approach 1:
The patent transforms the complex nonlinear radial distortion correction problem into a simpler tangential distortion correction problem by changing the coordinate system parameters. This allows the use of simpler algorithms while maintaining manufacturing precision for lenses with nonlinear radial distortion.
Solution Approach 2:
The patent introduces an intermediary coordinate transformation step that converts nonlinear radial distortion into tangential distortion representation. This intermediary approach simplifies the overall correction process and reduces algorithmic complexity while preserving dewarping accuracy.
2Manufacturing precision
If standard fisheye dewarping algorithms are used with nonlinear radial distortion, then manufacturing precision is maintained, but productivity decreases due to increased computational time
Solution Approach 1:
By changing the mathematical parameters and coordinate system representation, the patent converts a computationally intensive nonlinear radial distortion correction into a faster tangential distortion correction, thereby improving productivity while maintaining manufacturing precision.
Solution Approach 2:
The patent substitutes a complex computational mechanical process (nonlinear radial distortion correction) with a simpler computational approach (tangential distortion correction), reducing computational time and improving processing speed while maintaining accuracy.
3Manufacturing precision
If standard fisheye dewarping algorithms are used with nonlinear radial distortion, then manufacturing precision is maintained, but use of energy increases due to higher computational load
Solution Approach 1:
The patent changes the mathematical parameters of the distortion model from nonlinear radial to tangential distortion, which reduces the computational load on the GPU and thereby decreases energy consumption while maintaining the same manufacturing precision.
Data Source
AI summary
Systems and methods in accordance with various embodiments of the invention can generate term (or PolyMap) coefficients that properly calibrate any camera lens using information obtained from a calibration pattern (e.g., chessboard patterns). Term coefficients in accordance with several embodiments of the invention can be used to transform a warped image to a dewarped image by mapping image information from the warped image to the dewarped coordinates. Determining calibration coefficients in accordance with certain embodiments of the invention can include novel and inventive processes for capturing calibration images, processing the calibration images, and/or deriving inputs needed for proper calibration as described in this disclosure. Processes described in this description can provide for improvements in the field of image processing, especially in increasing the speed of dewarping processes and in the accurate capture of calibration pattern images.