Image processing algorithm for characterization of uniformity of printed images
US6571000B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 29, 1999 |
| Grant date | May 27, 2003 |
| Priority date | — |
| Expiry date | Nov 29, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T2207/30144
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
This invention specifically covers one of the many image quality (IQ) metrics that can be part of an overall image quality analysis engine. The specific problem with image quality addressed with this metric is that of a region of a printed (or copied) image, which was intended to have a uniform color, but which shows visible color variations. The color variation can have many different forms, both with respect to the type of color difference and with respect to the spatial nature of the non-uniformities. The image quality analysis system readily distinguishes between non-uniformities in the following different categories, including: (a) amplitude modulated cluster dot halftone patterns; (b) frequency modulated halftone patterns (e.g., stochastic screens); (c) irregular two-dimensional variations from noise; (d) isolated (non-periodic) one-dimensional streaks; (e) periodic, one-dimensional bands; and (f) two-dimensional periodic variations (Moire). The results from the image quality analysis can then be used as a basis for diagnosing machine problems.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.