Image processing apparatus
US5898507A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 12, 1994 |
| Grant date | Apr 27, 1999 |
| Priority date | — |
| Expiry date | Jul 12, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/40006
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In an image processing apparatus of this invention, an error diffusion processing means having a multi level signal conversion means changes the conversion characteristics of the multi level signal conversion means, e.g., corrects the output value of error diffusion processing, on the basis of an output from a means for detecting a variation in toner attachment amount or image forming condition. That is, this invention executes error diffusion processing as follows when an input dimension is different from an output dimension (e.g., input dimension=reflection factor or density, output dimension=number of gradation levels) with respect to a multi-value conversion means because error diffusion processing cannot be simply performed. The input dimension is set to coincide with the output dimension (an output signal is set to coincide with the input signal), this output signal is changed in accordance with a variation in image density, and an error between the changed output signal and the input signal is calculated, thereby executing error diffusion processing. Even when the gradation characteristics per pixel vary due to the influence of a change in environment or aging, or the number…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.