Monitoring camera apparatus

• US 9,025,026 B2
• Filed: 08/21/2012
• Issued: 05/05/2015
• Est. Priority Date: 08/01/2012
• Status: Active Grant

• Current Assignee: JAI Corporation Limited
• Original Assignee: JAI Corporation Limited
• Inventors: Takahashi, Hiroaki, Hasegawa, Takami, Kakinoki, Kenji
• Primary Examiner(s): Harold, Jefferey
• Assistant Examiner(s): DESIR, JEAN WICEL
• Application Number:
  US13/811,857
• Publication Number:
  US 20140192190A1
• Time in Patent Office: 987 Days
• Field of Search: 348/143, 348/135, 348/144, 348/149, 348/148, 348/169, 348/180, 340/907, 340/937, 340/469, 340/458
• US Class Current: 348/143
• CPC Class Codes: G06V 10/141 Control of illumination
• CPC Class Codes: G06V 20/584 of vehicle lights or traffic lights
• CPC Class Codes: H04N 23/84 for processing colour signals
• CPC Class Codes: H04N 7/18 Closed-circuit television [CCTV] systems, i.e. systems in which the video signal is not broadcast

Abstract

Provided is a monitoring camera apparatus that can pick up, when an image of a signal lamp of a traffic signal is picked up by a monitoring camera at night, an image of an image pickup region other than the signal lamp bright without saturating a red signal lamp.

The monitoring camera apparatus includes signal controlling means including RGB ratio detecting means for detecting lighting, lighting/extinguishing times, the shape and the number, or signal lamp control signals of signal lamps of a traffic signal in the image pickup region and detecting ratios of RGB signals of the signal lamps, gain controlling means for controlling a gain of the RGB signals, and color mixture controlling means for controlling color mixtures of respective signal lamp colors. The signal controlling means detects ratios of RGB signal levels on the basis of lighting, lighting/extinguishing times, the shape and the number, or signal lamp control signals of respective signal lamps of green, yellow, and red, specifies the signal lamps as a red signal lighting region of a red signal lamp if R>G≈B, attenuates GB signals or reduces the GB signals to zero and reduces color mixture in the color signal lighting region with the color mixture controlling means, and makes it possible to display lighting of the red signal lamp as a red color on a monitor.

Claims

1. A monitoring camera apparatus comprising:

a solid-state image pickup device; and

signal controlling means corresponding to each of RGB signals of an object image output from the solid-state image pickup device, the monitoring camera apparatus monitoring a street including a traffic signal, wherein

the signal controlling means includes;

signal lamp detecting means for detecting lighting of signal lamps including LED light-emitting devices of a traffic signal present in an image pickup region of the solid-state image pickup device;

lighting/extinguishing region detecting means for detecting a lighting/extinguishing region for periodically repeating lighting, extinguishing, and lighting of the detected signal lamps;

RGB ratio detecting means for detecting ratios of RGB signals of the lighting/extinguishing region output from the lighting/extinguishing region detecting means;

color mixture controlling means for controlling color mixture of signal lamp colors; and

gain controlling means for controlling a gain of the RGB signals,

the signal lamp detecting means detects, on the basis of a spectral sensitivity characteristic of the solid-state image pickup device and a light emission wavelength characteristic of the LED light-emitting devices of each of the RGB signals output from the solid-state image pickup device, three regions indicated by xy coordinate values of pixels arrayed in a lateral direction or a longitudinal direction in the image-pickup region and in series and periodically repeatedly lit and extinguished,

the lighting/extinguishing region detecting means specifies, on the basis of the regions indicated by the xy coordinate values of the pixels output from the signal lamp detecting means, the three lit/extinguished lighting/extinguishing regions and sends the lighting/extinguishing regions to the RGB ratio detecting means,

the RGB ratio detecting means compares levels of the RGB signals during the lighting of the lighting/extinguishing regions and detects the signal lamp as a red signal lamp if R>

G≈

B, as a yellow signal lamp if R>

G>

B, and as a green signal lamp if G>

B>

R,

the RGB ratio detecting means further specifies, on the basis of a region indicated by the xy coordinate value of the pixel of the lighting/extinguishing region having a signal level of R>

G≈

B, the region as a red signal lighting region and sends the red signal lighting region to the color mixture controlling means,

the color mixture controlling means attenuates GB signals in the red signal lighting region or reduces the GB signals to zero, reduces color mixture in the red signal lighting region, and sends the RGB signals to the gain controlling means, and

the gain controlling means controls an input R signal to enable a lighting region of the red signal lamp to be displayed as a proper red color on a monitor.

2. The monitoring camera apparatus according to claim 1, wherein the RGB ratio detecting means compares, on the basis of a region indicated by the xy coordinate values of the pixels that output signals in synchronization with lighting times of green, yellow, and red signal lamps of the traffic signal, respective RGB signal levels in the specified lighting/extinguishing region of the respective signal lamps of green, yellow, and red, specifies the lighting/extinguishing region as a red signal lighting region if R>

G≈

B, attenuates GB signals in the red signal lighting region or reduces the GB signals to zero and reduces color mixture in the red signal lighting region with the color mixture controlling means, and makes it possible to display lighting of the red signal lamp as a red color on the monitor.

3. The monitoring camera apparatus according to claim 1, wherein the RGB ratio detecting means compares, on the basis of a region indicated by the xy coordinate values of the pixels where an output signal level changes in synchronization with a lighting/extinguishing time or a lighting/extinguishing time interval of each of green, yellow, and red signal lamps of the traffic signal, RGB signal levels in the specified lighting/extinguishing region of the respective signal lamps of green, yellow, and red, specifies the region as a red signal lighting region if R>

G≈

B, attenuates GB signals in the red signal lighting region or reduces the GB signals to zero and reduces color mixture in the red signal lighting region with the color mixture controlling means, and makes it possible to display lighting of the red signal lamp as a red color on the monitor.

4. The monitoring camera apparatus according to claim 1, wherein the signal controlling means includes saturated region detecting means for detecting a saturated region of the RGB signals, when the saturated region of the RGB signals is detected by the saturated region detecting means according to sensitivity raising control at night or during rainy weather, the signal controlling means attenuates a signal level to be equal to or lower than a saturated level with the electronic shutter controlling means of the solid-state image pickup device and the gain controlling means, and the RGB ratio detecting means compares, on the basis of a region indicated by the xy coordinate values of the pixels where an output signal level changes in synchronization with a lighting/extinguishing time or a lighting/extinguishing time interval of each of green, yellow, and red signal lamps of the traffic signal, RGB signal levels in the specified lighting/extinguishing region of the respective signal lamps of green, yellow, and red, specifies the region as a red signal lighting region if R>

G≈

B, attenuates GB signals in the red signal lighting region or reduces the GB signals to zero and reduces color mixture in the red signal lighting region with the color mixture controlling means, and makes it possible to display lighting of the red signal lamp as a red color on the monitor.

5. The monitoring camera apparatus according to claim 1, wherein the signal controlling means recognizes a shape of the signal lamps of the traffic signal, compares RGB signal levels of the respective signal lamps of green, yellow, and red in a portion of the shape, specifies the portion as a red signal lighting region if R>

G≈

B, attenuates GB signals in the red signal lighting region or reduces the GB signals to zero and reduces color mixture in the red signal lighting region with the color mixture controlling means, and makes it possible to display lighting of the red signal lamp as a red color on the monitor.

6. The monitoring camera apparatus according to claim 1, wherein the signal controlling means includes saturated region detecting means for detecting a saturated region of the RGB signals, when the saturated region of the RGB signals is detected by the saturated region detecting means according to sensitivity raising control at night or during rainy weather, the signal controlling means attenuates a signal level to be equal to or lower than a saturated level with the electronic shutter controlling means of the solid-state image pickup device and the gain controlling means and then recognizes a shape of the signal lamps of the traffic signal, compares RGB signal levels of the respective signal lamps of green, yellow, and red in a portion of the shape, specifies the portion as a red signal lighting region if R>

G≈

B, attenuates GB signals in the red signal lighting region or reduces the GB signals to zero and reduces color mixture in the red signal lighting region with the color mixture controlling means, and makes it possible to display lighting of the red signal lamp as a red color on the monitor.

7. The monitoring camera apparatus according to claim 1, wherein the signal controlling means receives blinking control signals of the signal lamps of the traffic signal, specifies the red signal lamp lit on the basis of a blinking control signal of the red signal lamp as a red signal lighting region, attenuates GB signals in the red signal lighting region or reduces the GB signals to zero and reduces color mixture in the red signal lighting region with the color mixture controlling means, and makes it possible to display lighting of the red signal lamp as a red color on the monitor.

8. The monitoring camera apparatus according to claim 1, wherein the signal controlling means stores, in a memory, the red signal lighting region specified as a red signal lighting region of a red signal from RGB signal ratios of the signal lamps of the traffic signal not saturated in the daytime, attenuates GB signals in the red signal lighting region or reduces the GB signals to zero and reduces color mixture in the red signal lighting region with the color mixture controlling means on the basis of the red signal lighting region always read out from the memory, and makes it possible to display lighting of the red signal lamp as a red color on the monitor.

9. The monitoring camera apparatus according to claim 8, wherein the signal controlling means stores, in a memory, respective RGB signal levels during lighting and during extinguishing of the signal lamps of the traffic signal and subtracts the RGB signal levels during the extinguishing from the RGB signal levels during the lighting on the basis of respective signal levels during the lighting and during the extinguishing of the signal lamps read out from the memory.