Patent ID: 7471848
Filing Date: 2008-12-30
Classification: G06T,H04N

Abstract:
1. A computer readable medium encoded with a program for correcting image distortion on a computer comprising: an image input function that inputs a picked-up image in which a paper face has been imaged, the paper face having at least character strings or ruled lines; a geodesic line projection extraction function that extracts from the image that has been input by said image input function, a projection set of geodesic lines which are parallel with each other on a curved surface of the paper face, using at least the character strings or ruled lines of said paper face as a clue; a ruling line projection extraction function that extracts from the projection set of geodesic lines that has been extracted by said geodesic line projection extraction function, a projection set of ruling lines that form a ruled surface corresponding to said curved surface of the paper face; a paper face curved surface estimating function that estimates said curved surface of the paper face from the projection sets of the geodesic lines and the ruling lines extracted by said geodesic line projection extraction function and said ruling line projection extraction function, respectively; and a distortion correction function for correcting distortion of the image input by said image input function, based on the curved surface of the paper face estimated by said paper face curved surface estimating function.