DETERMINATION OF ASPECT RATIO FROM PERSPECTIVE PROJECTION IMAGES

摘要

PURPOSE: A method for determining an aspect ratio for a square document projected on a camera is provided to determine an aspect ratio of a square document by applying a square feature of a planar document to a 3D perspective projection method to correct a document using the aspect ratio, thereby increasing the readability of a document. CONSTITUTION: The direction of one of two straight line pairs is found using an image projected on a camera(S100). The two straight line pairs forms a square document. A direction of the other straight line pair is found using the same method as above(S200). The direction of a 3D planar surface, where the square document is located, is determined using the directions(S300). An aspect ratio for the square document is determined using the directions(S400).