Method and apparatus for extracting information from a target area within a two-dimensional graphical object in an image

摘要

A method is presented for extracting information from a target area (101) within a two-dimensional graphical object (100) having a plurality of predetermined features (23) with known characteristics in a first plane. An image (102) is read where the object (100) is located in a second plane, which is a priori unknown. A plurality of candidates (108) to the features in the second plane are identified in the image. A transformation matrix (H) for projective mapping between the second and first planes is calculated from the identified feature candidates. The target area (101) of the object is transformed from the second plane into the first plane. Finally, the target area is processed so as to extract the information.