Nonliner calibration of output devices
US5953498A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 2, 1997 |
| Grant date | Sep 14, 1999 |
| Priority date | — |
| Expiry date | May 2, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/407
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method for the nonlinear calibration of digital image data without the introduction of tonal loss is applied to image data in a computer-to-printing press system. Apparatus for implementing this method is provided. Computer processed graphics, provided from the computer in 8-bit format, are converted into 16-bit format. This 16-bit image data is then calibrated to compensate for anticipated press gain. The calibration translates the image data according to a desired nonlinear cutback (value reduction) curve of gray value reduction. Calibrated image data is then passed through 16-bit halftoning screening, the output from which is provided to the imagesetter. The implemention may include a general purpose computer with specific software resident therein, or dedicated hardware including a series of encoders and look-up table implementaion devices. Alternatively, or supplementally, the laser exposure in the image setter may be increased to contribute substitute or supplemental analog nonlinear gray value reduction.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.