Method and device for correcting document image captured by image pick-up device
US10187546B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 19, 2017 |
| Grant date | Jan 22, 2019 |
| Priority date | — |
| Expiry date | Apr 30, 2037 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/3935
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The present application relates to a method and a device for correcting a document image captured by an image pick-up device. The method includes: determining world coordinates of four vertices of the document image; calculating an original aspect ratio of the document image based on a correspondence between the world coordinates of the four vertices and projective coordinates of the four vertices in a projective space, and an intrinsic matrix and characteristics of an extrinsic matrix of the image pick-up device; determining a projective transformation matrix based on the world coordinates of the four vertices and the aspect ratio; and obtaining a corrected document image based on the determined projective transformation matrix and the document image. According to the application, perspective transformation can be corrected by using only one captured image and an original image can be recovered based on an original aspect ratio.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.