An automatic grid corner extraction technique for camera calibration

Camera calibration is essential for many computer vision and image processing applications. However, this calibration process can be rather time consuming and may require a significant amount of human intervention. Calibration models traditionally employ a calibration grid whose four corner points must be marked by hand on a per-frame basis. The objective of this work is to develop a technique for processing these frames rapidly, with as little human intervention as possible. We propose an algorithm to extract the boundaries of the calibration grid automatically, based on a spectral analysis of HD (high-definition) video frames. The accuracy of the intrinsic parameters estimated using our automatic method is evaluated through comparison with those obtained using a method that requires hand labeling of the corner points.