Image processing apparatus and method for accurately detecting character edges
US7355755B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 3, 2002 |
| Grant date | Apr 8, 2008 |
| Priority date | — |
| Expiry date | Feb 6, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06V30/10
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An image processing apparatus includes an edge amount calculating device configured to calculate edge amounts of an image in a plurality of directions for each of a plurality of frequency bands of the image. A character edge area determination device determines, based on the calculated edge amounts, whether or not a selected picture element of the image is of a character edge area. A sharpness control device corrects a frequency characteristic of the image by performing a first correction to the edge amounts when the selected picture element is determined to be of a character edge area by the character edge area determining device, and by performing a second correction to the edge amounts when the selected picture element is determined not to be of a character edge area by the character edge area determining device.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.