Image conversion device

TLDR: In this paper, the authors proposed a method to reduce the load of operation for cutting an optional part from a distorted circular image taken by a fish-eye lens and converting it to a planar regular image with minimized distortion.

Abstract: PROBLEM TO BE SOLVED: To reduce the load of operation for cutting an optional part from a distorted circular image taken by a fish-eye lens and converting it to a planar regular image with minimized distortion. SOLUTION: An image conversion device stores a distorted circular image in a memory 220. When a user designates a cut-out center point PP, a magnification m, and a planar inclination ϕ to a unit 110, rotational coefficients A-F are calculated in a coefficient calculation section 240. A coordinate conversion section 270 performs mutual conversion of a coordinate (x, y) within the memory 220 and a coordinate (u, v) within a memory 230 by a conversion expression using the coefficients A-F to obtain a planar regular image. When a fish-eye lens other than an orthographic system is used, projection system conversion by conversion sections 210 and 280 is performed to apply a conversion expression of orthographic system. When the coordination conversion in the coordinate conversion section 270 or the projection system conversion in the conversion section 280 is performed, processing referring to a preliminarily prepared table is substituted for operation including extraction of square root or calculation of inverse to reduce the operation load. COPYRIGHT: (C)2011,JPO&INPIT