Dual spectral band network camera

• US 20050140786A1
• Filed: 07/14/2004
• Published: 06/30/2005
• Est. Priority Date: 07/14/2003
• Status: Active Grant

• Current Assignee: Arecont Vision Costar, LLC (Costar Technologies, Inc.)
• Original Assignee: Arecont Vision LLC (Costar Technologies, Inc.)
• Inventors: Kaplinsky, Michael
• Granted Patent: US 7,492,390 B2
• Time in Patent Office: Days
• US Class Current: 348/207.100
• CPC Class Codes: H04N 23/11 for generating image signals from visible and infrared light wavelengths
• CPC Class Codes: H04N 23/66 Remote control of cameras or camera parts, e.g. by remote control devices
• CPC Class Codes: H04N 23/661 Transmitting camera control signals through networks, e.g. control via the Internet
• CPC Class Codes: H04N 23/84 for processing colour signals

Abstract

The subject of this invention is the network camera sensitive to both visual and near-infrared or infrared spectral bands and comprising two or more image sensors with different spectral responses, one or more image processors, and network interfaces. In the preferred embodiment the network camera disclosed in this invention comprises two image sensors with individual optics, where both sensors have similar fields of view. In the preferred embodiment of the present invention one of the sensors is color image sensor with infrared-cut filter positioned in front of pixel array, while the other sensor is monochrome image sensor with optics characterized by lower f-number than that used for color sensor and without infrared-cut filter in its field of view. In one of the embodiments of this invention, monochrome sensor has larger pixel sizes than color sensor to provide for higher low-light sensitivity.

Claims

1. Dual spectral band network video camera comprising two or more image sensors characterized by distinctly different sensitivities to the intensity of illumination incident on said image sensors, network interface for transmission off camera of image data streams originated by said image sensors and the means of multiplexing of said image data streams into said network interface.

2. Dual spectral band network camera of claim 1, wherein at least one of the said image sensors is a color image sensor and wherein at least one of the said image sensors is a monochrome image sensor.

3. Dual spectral band network camera of claim 1, wherein all of the said image sensors have substantially similar fields of view.

4. Dual spectral band network camera of claim 2, wherein an infra-red cut filter is positioned in front of focal plane array of said color image sensor and wherein there is no infra-red cut filter positioned in front of focal plane array of said monochrome image sensor.

5. Dual spectral band network camera of claim 2, wherein said monochrome image sensor comprises pixels with larger light sensitive area than light sensitive area of the pixels of said color image sensor.

6. Dual spectral band network camera of claim 2, wherein said color image sensor is a high-resolution image sensor comprising more than 1 million pixels.

7. Dual spectral band network camera of claim 1, wherein individual optics or lens is positioned in front of the focal plane arrays of each of said image sensors and wherein said optics or lens positioned in front of more light sensitive image sensor has lower f-number than said optics positioned in front of less light sensitive image sensor.

8. Dual spectral band network camera of claim 1, wherein said network interface is Ethernet network interface.

9. Dual spectral band network camera of claim 1, wherein said network interface supports one or more of the following standard network protocols:

TCP, UDP, TFTP, IP.

10. Dual spectral band network camera of claim 1, wherein said multiplexing of said image data streams is performed on a time-interleaved basis, where transmission of some portion of data stream from one of the said image sensors is followed by the transmission of some portion of data stream from another of said image sensors.

11. Dual spectral band network camera of claim 1, wherein said means of multiplexing of image data streams are configured to allow for selection of the image data streams to be transmitted off camera to be controlled from an external input.

12. Dual spectral band network video camera comprising two or more image sensors characterized by distinctly different sensitivities to the intensity of illumination incident on said image sensors, network interface for transmission off camera of image data streams originated by said image sensors, the means of multiplexing of said image data streams into said network interface and one or more image processors, wherein one of said image processors is equipped to perform image compression of images originated by said image sensors.

13. Dual spectral band network camera of claim 12, wherein said image data streams from said image sensors are ultimately multiplexed into a single image processor equipped to perform image compression.

14. Dual spectral band network camera of claim 12, wherein said image processors further comprise image pre-processors, wherein image data streams from each of the said image sensors are independently processed by distinct image pre-processors and then multiplexed into common to all said image sensors image post-processor equipped to perform image compression.

15. Dual spectral band network camera of claim 12, wherein said image data streams are multiplexed into a single image processor equipped to bypass color-related processing steps during the processing of the monochrome images.

16. Dual spectral band network camera of claim 12, wherein said multiplexing of said image data streams is performed on a time-interleaved basis, where transmission of some portion of data stream from one of the said image sensors is followed by the transmission of some portion of data stream from another of said image sensors.

17. Dual spectral band network camera of claim 12, wherein one of the said image processors is common to all said image sensors.

18. Dual spectral band network camera of claim 17, wherein said image processor is common equipped to determine the intensity of incident on the camera illumination by means of monitoring the exposure time of the said imagers and wherein said processor selects the images to be transmitted from the camera, wherein low illumination causes the images originated from image sensors with higher light sensitivity to be transmitted.

19. Dual spectral band network camera of claim 12, wherein said means of multiplexing of image data streams are configured to allow for selection of the image data streams to be transmitted off camera to be controlled from an external input.

20. Dual spectral band network camera of claim 12, wherein said image compression is JPEG.

21. Dual spectral band network camera of claim 12, wherein said image compression is MPEG.

22. Dual spectral band network camera of claim 12, wherein one or more of said image processors are equipped to increase the intra-scene dynamic range of the images, wherein said intra-scene dynamic range is largest difference in the intensity of illumination of the objects in the field of view of said imagers that can be discerned from the inspection of the image.

23. Dual spectral band network camera of claim 12, wherein said image processors comprise dedicated logic that implements image processing pipelines, wherein image pixels are operated on by the sequential stages of said image processing pipelines with each pipeline stage operating concurrently with all or most of the other pipeline stages.

24. Dual spectral band network camera of claim 12, wherein at least one of the said image sensors is a color image sensor and wherein at least one of the said image sensors is a monochrome image sensor.

25. Dual spectral band network camera of claim 12, wherein all of the said image sensors have substantially similar fields of view.

26. Dual spectral band network camera of claim 24, wherein an infra-red cut filter is positioned in front of focal plane array of said color image sensor and wherein there is no infra-red cut filter positioned in front of focal plane array of said monochrome image sensor.

27. Dual spectral band network camera of claim 24, wherein said monochrome image sensor comprises pixels with larger light sensitive area than light sensitive area of the pixels of said color image sensor.

28. Dual spectral band network camera of claim 24, wherein said color image sensor is a high-resolution image sensor comprising more than 1 million pixels.

29. Dual spectral band network camera of claim 12, wherein individual optics or lens is positioned in front of the focal plane arrays of each of said image sensors and wherein said optics or lens positioned in front of more light sensitive image sensor has lower f-number than said optics positioned in front of less light sensitive image sensor.

30. Dual spectral band network camera of claim 12, wherein said network interface is Ethernet network interface.

31. Dual spectral band network camera of claim 12, wherein said network interface supports one or more of the following standard network protocols:

TCP, UDP, TFTP, IP.

32. Camera system comprising:

dual spectral band network video camera comprising two or more image sensors characterized by distinctly different sensitivities to the intensity of illumination incident on said image sensors, network interface for transmission off camera of image data streams originated by said image sensors, the means of multiplexing of said image data streams into said network interface and one or more image processors, wherein one of said image processors is equipped to perform image compression of images originated by said image sensors; and

wherein said camera system also comprises computer system receiving the images and software running on said computer system, wherein said software is configured to determine the intensity of incident on the camera illumination by means of monitoring the exposure time of said image sensors and wherein said software selects the images to be transmitted from the camera, wherein low illumination causes the images originated from image sensors with higher light sensitivity to be transmitted.

33. Camera system of claim 32, wherein said software controls the operation of said camera by means of transmitting the commands to the camera by means of said network interface.