Method of correcting an image with perspective distortion and producing an artificial image with perspective distortion

• US 6,947,610 B2
• Filed: 03/01/2002
• Issued: 09/20/2005
• Est. Priority Date: 03/02/2001
• Status: Expired due to Fees

• Current Assignee: Corel Corporation (Corel Holdings LP)
• Original Assignee: Ulead Systems, Inc (Corel Holdings LP)
• Inventors: Sun, Hung-Ming
• Primary Examiner(s): Mancuso, Joseph
• Assistant Examiner(s): Seth, Manav
• Application Number:
  US10/085,409
• Publication Number:
  US 20030002751A1
• Time in Patent Office: 1,299 Days
• Field of Search: 382/293, 382/295, 382/296, 382/275, 382/298, 353/69
• US Class Current: 382/293
• CPC Class Codes: G06T 3/00 Geometric image transformations in the plane of the image

Abstract

A method of correcting an image with perspective distortion and creating an artificial image with perspective distortion is disclosed. First, image data including a distorted object image are received. Next, the user inputs an operational instruction for setting a plurality of distortion parameters pertaining to the image data, which include a distorted side of the distorted object image, a central line and a distortion ratio. Thus, a plurality of coordinates of corners of the distorted object image are calculated according to these distortion parameters and a transformation matrix is determined according to the calculated coordinates of the corners of the distorted object image. Finally, the distorted object image is transformed to a corrected object image according to the transformation matrix.

Claims

1. A method of correcting an image with perspective distortion, comprising the steps of:

receiving image data including a distorted object image, wherein the distorted object image is perspective from a projection plane;

setting distortion parameters pertaining to the image data according to an operational instruction, wherein the distortion parameters comprise a distortion central line perpendicular to the projection plane and passing through a coverage point of any set of parallel lines that are not parallel to the projection plane;

calculating a plurality of coordinates of corners of the distorted object image according to the distortion parameters;

determining a transformation matrix according to the calculated coordinates of the corners of the distorted object image; and

transforming the distorted object image to a corrected object image according to the transformation matrix.

2. The method of claim 1, wherein the distortion parameter includes a distortion ratio of a distorted side of the distorted object image.

3. The method of claim 1, wherein the coordinates of the corners of the corrected object image are calculated according to the location of the distortion central line of the distorted object image.

4. The method of claim 1, wherein the distortion parameter includes a distorted side of the distorted object image, a distortion ratio of the distorted side of the distorted object image and a location of a distortion central line of the distorted object image.

5. A method of determining coordinates of corners of a distorted object image on an image with perspective distortion, comprising the steps of:

determining a distorted side of the distorted object image, wherein the distorted object image is perspective from a projection plane;

determining a location of a distortion central line of the distorted object image with respect to the distorted side and a distortion ratio of the distorted object image with respect to the distorted side, wherein the distortion central line is perpendicular to the projection plane and passes through a coverage point of any set of parallel lines that are not parallel to the projection plane; and

calculating the coordinates of the corners of the distorted object image according to the distorted side, the location of the distortion central line and the distortion ratio.