Image processing apparatus including low-linear-density dot region detection unit, and image forming apparatus including the same
US6655861B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | May 23, 2002 |
| Grant date | Dec 2, 2003 |
| Priority date | — |
| Expiry date | May 23, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T5/20
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An image processing apparatus includes a maximum/minimum density detecting unit which detects a center pixel of a matrix of N×N pixels in image data that has a maximum or minimum density. A determination unit determines whether the absolute value of a difference between an average of densities of diagonal pixels of the matrix and a density of the center pixel is larger than a threshold value. A peak pixel detecting unit detects peak pixels of the matrix, each peak pixel being the center pixel having a maximum or minimum density, and the absolute value of the difference with respect to the center pixel being larger than the threshold value. A dot region detecting unit detects one of neighboring pixels of the matrix as being a dot region based on the number of the peak pixels in a target region and the number of the peak pixels in each of neighboring regions.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.