MATLAB-Based Calibration Program: Corner Detection and Zhang's Calibration Algorithm with GUI

I developed a comprehensive calibration program in MATLAB that integrates corner detection functionality with Zhang Zhengyou's robust camera calibration algorithm. The program features an intuitive graphical user interface designed to simplify the calibration workflow for users across various proficiency levels. For corner detection, I implemented an efficient algorithm utilizing MATLAB's image processing toolbox, specifically employing techniques like Harris corner detection or Shi-Tomasi corner detection with sub-pixel accuracy enhancement. The algorithm processes input images to automatically identify checkerboard pattern intersections with high precision. Regarding Zhang's calibration algorithm implementation, I incorporated the complete mathematical framework including: - Initial estimation of homography matrices between calibration patterns and image planes - Closed-form solution for intrinsic parameters using constraints on the homography matrices - Nonlinear optimization using Levenberg-Marquardt algorithm to refine camera parameters - Radial and tangential distortion coefficient estimation The calibration workflow is structured as follows: 1. Image acquisition from multiple viewpoints 2. Automated corner detection and coordinate extraction 3. Initial parameter estimation using linear least squares 4. Nonlinear refinement minimizing reprojection errors 5. Validation through reprojection error analysis Key MATLAB functions employed include: - `detectCheckerboardPoints()` for automated corner detection - `estimateCameraParameters()` implementing Zhang's method - Custom GUI components using App Designer for intuitive parameter adjustment - Visualization tools for displaying reprojection errors and calibration results This calibration solution provides researchers and engineers with an accurate, efficient tool for camera parameter estimation, suitable for both academic research and industrial computer vision applications. The program outputs complete camera intrinsic parameters (focal length, principal point, skew) and distortion coefficients with statistical validation metrics.