Enhanced sensitivity color video camera with reduced red component in second luminance signal
US4688085A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 16, 1985 |
| Grant date | Aug 18, 1987 |
| Priority date | — |
| Expiry date | Jul 16, 2005 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N25/133
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A color video camera uses an infrared cut-off filter, a complementary filter and a solid state image pick-up device. The infrared cut-off filter cuts off near infrared light of image above a wavelength .lambda.c, which is set in the range of 670 nm.ltoreq..lambda.c.ltoreq.780 nm. A color sampling/generating circuit has a matrix circuit connected to the solid state image pick-up device for providing a first luminance signal, a second luminance signal, a red channel signal and a blue channel signal. The second luminance signal is used for producing a red color difference signal and a blue color difference signal by using the red channel signal and the blue channel signal in a processing circuit. In the matrix circuit, matrix coefficients for producing the second luminance signal are set to reduce the red component of the second luminance signal. Further, the red color difference signal below a predetermined value is extracted and added to the first luminance signal to reduce the red component of the first luminance signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.