Region-based adaptive automatic focal-length estimation method for fisheye-lens distortion correction

This paper presents an automatic region-adaptive focal-length estimation method to correct a fisheye-lens distortion. The proposed method consists of three steps; i) generation of criteria for estimating focal-length, ii) region-adaptive focal-length estimation, and iii) correction of the fisheye lens distortion using the orthographic projection model. Experimental result show that the proposed method provides a lower loss rate than existing methods.