Image processing apparatus with fixed or variable threshold
US5086484A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 21, 1989 |
| Grant date | Feb 4, 1992 |
| Priority date | — |
| Expiry date | Aug 21, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/4053
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An image processing apparatus of this invention is arranged so that a threshold for use in binarization is switched between two types in accordance with whether or not a portion in which input pixel data is located is positioned in the vicinity of an edge portion of an image. One type is a threshold which varies in the width of variation corresponding to the density of the input pixel, while the other type is a fixed threshold. If an objective pixel is located in the vicinity of an edge portion of an image, binarization is carried out with the fixed threshold, while if the objective pixel is located in a non-edge portion, the variable threshold is used.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.