Calibration pattern and method for matching characteristics of video monitors and cameras
US4760447A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 31, 1986 |
| Grant date | Jul 26, 1988 |
| Priority date | — |
| Expiry date | Jul 31, 2006 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N17/04
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A calibration pattern (FIG. 2) is utilized to adjust the calibration of a video monitor (C) and a multi-format camera (D). The multi-format camera (D) includes a video display (12) and photographic equipment (20) internally therein such that received signals indicative of an image are turned into a photograph. The test pattern includes a first region (30) having a background (34) and a series of holes or dots (36) thereon. Each hole has progressively greater contrast with the first background such that the number of visible holes is indicative of whether the video monitor and multi-format camera are in proper calibration. A second region (40) is similar to the first region but has gray holes on a white background. A third region (50) has a plurality of tuning fork-like subregions having different gray scales levels. The brightness of a fourth region (70) varies sinusoidally. A fifth region (80) has square holes and a sixth region (90) has circular holes. The holes are of incrementally displaced brightness levels against a black or white background. The camera is initially calibrated in a conventional manner using photodensitometer measurements. To verify the calibration subsequentl…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.