Method of and apparatus for processing an image
US5583661A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 13, 1994 |
| Grant date | Dec 10, 1996 |
| Priority date | — |
| Expiry date | Sep 13, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/4056
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An image is processed by using an error diffusion method of propagating density distribution errors in pixels around a pixel to be noted. A method includes the steps of calculating thresholds (Th.sub.1, Th.sub.2) of densities corresponding to the area ratio between the pixels; selecting a pixel to be noted (f) which are different in the area ratio from each other; calculating errors (E) produced in the peripheral pixels according to the distances from the peripheral pixels to the noted pixel and areas of the individual peripheral pixels; adding the propagated errors to a density of the noted pixel so as to make a rearrangement (f') on the density of the noted pixel; comparing the rearranged density of the noted pixel with the thresholds to obtain a corresponding level (G) represented in a binary form, and obtaining density distribution errors (e).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.