DRIVER ASSISTANCE SYSTEM FOR A VEHICLE

• US 20130138294A1
• Filed: 01/25/2013
• Published: 05/30/2013
• Est. Priority Date: 03/25/1996
• Status: Active Grant

• Current Assignee: Magna Electronics Incorporated (Magna International Incorporated)
• Original Assignee: Donnelly Corporation (Magna International Incorporated)
• Inventors: Schofield, Kenneth, Larson, Mark L., Vadas, Keith J.
• Granted Patent: US 8,492,698 B2
• Time in Patent Office: Days
• US Class Current: 701/36
• CPC Class Codes: B60Q 1/14 having dimming means
• CPC Class Codes: B60Q 1/143 combined with another condition, e.g. using vehicle recognition from camera images or activation of wipers
• CPC Class Codes: B60Q 2300/052 Switching delay, i.e. the beam is not switched or changed instantaneously upon occurrence of a condition change
• CPC Class Codes: B60Q 2300/312 Adverse weather
• CPC Class Codes: B60Q 2300/314 Ambient light
• CPC Class Codes: B60Q 2300/3321 Detection of streetlights
• CPC Class Codes: B60Q 2300/41 preceding vehicle
• CPC Class Codes: B60Q 2300/42 oncoming vehicle
• CPC Class Codes: B60Q 2400/30 Daytime running lights [DRL], e.g. circuits or arrangements therefor
• CPC Class Codes: G05D 1/0244 using reflecting strips
• CPC Class Codes: G06V 10/143 Sensing or illuminating at different wavelengths
• CPC Class Codes: G06V 20/56 exterior to a vehicle by using sensors mounted on the vehicle
• CPC Class Codes: G06V 20/582 of traffic signs
• CPC Class Codes: G06V 20/584 of vehicle lights or traffic lights
• CPC Class Codes: H04N 7/18 Closed-circuit television [CCTV] systems, i.e. systems in which the video signal is not broadcast

Abstract

A driver assistance system for a vehicle includes a bracket attached at a windshield of a vehicle and a housing mounted to the bracket and an imager disposed in the housing. The imager may include (i) a two-dimensional CMOS photosensor array of photosensor elements and/or (ii) a lens. With the housing mounted to the bracket attached at the vehicle windshield, the imager views to the exterior of the vehicle through the vehicle windshield at a region of the windshield that may be swept by a windshield wiper of the vehicle. The photosensor array is operable to capture image data. A control includes an image processor disposed in the housing. The image processor includes a digital signal processor. The driver assistance system identifies objects viewed by the imager via processing by the image processor of captured image data. A spectral filter may be disposed between the photosensor array and the lens.

Claims

1. A driver assistance system for a vehicle, said driver assistance system comprising:

a bracket attached at a windshield of a vehicle equipped with said driver assistance system;

a housing mounted to said bracket;

an imager disposed in said housing;

said imager comprising (i) a two-dimensional CMOS photosensor array of photosensor elements and (ii) a lens;

wherein, with said housing mounted to said bracket attached at the vehicle windshield, said imager views to the exterior of the equipped vehicle through the windshield of the equipped vehicle at a region of the windshield that is swept by a windshield wiper of the equipped vehicle;

wherein said photosensor array is operable to capture image data;

a control comprising an image processor;

wherein said image processor is disposed in said housing;

wherein said image processor comprises a digital signal processor;

wherein said driver assistance system identifies objects viewed by said imager via processing by said image processor of captured image data;

wherein a spectral filter is disposed between said photosensor array and said lens; and

wherein said spectral filter provides red spectral filtering at some of said photosensor elements and not at others of said photosensor elements.

2. The driver assistance system of claim 1, wherein said control at least one of (a) controls a headlight of the equipped vehicle at least in part as a function of a speed of the equipped vehicle, (b) controls a headlight of the equipped vehicle at least in part in response to said image processing, (c) controls a speed of the equipped vehicle at least in part in response to said image processing, (d) generates an alert to the driver of the equipped vehicle responsive at least in part to image processing by said image processor, (e) responsive at least in part to image processing by said image processor, warns the driver of the equipped vehicle, (f) responsive at least in part to image processing by said image processor, decelerates the equipped vehicle, and (g) responsive at least in part to image processing by said image processor, stops the equipped vehicle.

3. The driver assistance system of claim 1, wherein said control controls a headlight of the equipped vehicle responsive, at least in part, to identification of at least one of (i) a headlight of an approaching vehicle in the forward field of view of said imager and (ii) a taillight of a leading vehicle in the forward field of view of said imager, and wherein said control is operable to at least one of (a) adjust an aim of the headlight of the equipped vehicle, (b) adjust an intensity of the headlight of the equipped vehicle, (c) adjust a pattern of the headlight of the equipped vehicle, (d) switch between a daytime running light condition and another lighting condition, (e) adjust a beam condition of the headlight of the equipped vehicle and (f) adjust a beam of the headlight of the equipped vehicle.

4. The driver assistance system of claim 1, wherein said photosensor array is operable to capture frames of image data at first and second exposure periods and wherein said first exposure period is shorter than said second exposure period.

5. The driver assistance system of claim 4, wherein said driver assistance system is operable to identify headlights of approaching vehicles responsive to processing of image data captured at said first exposure period and taillights of leading vehicles responsive to processing of image data captured at said second exposure period.

6. The driver assistance system of claim 1, wherein at least one of (a) identification of objects is based at least in part on a spectral characteristic of objects present in the forward field of view of said imager, and (b) identification of objects is based at least in part on said control determining that spatially adjacent regions of the forward field of view of said imager include objects having a particular spectral characteristic.

7. The driver assistance system of claim 1, wherein said control determines if a particular object present forward of the equipped vehicle has a particular spectral characteristic by comparing levels of light sensed by photosensor elements which respond to light in a red spectral region with levels of light sensed by photosensor elements which respond to light in a different spectral region.

8. The driver assistance system of claim 7, wherein said particular object present forward of the equipped vehicle comprises one of (i) an approaching headlight, (ii) a leading taillight, (iii) a lane marker, (iv) a traffic sign, (v) a traffic light, (vi) a stop sign and (vii) a caution sign.

9. The driver assistance system of claim 1, wherein at least one of (a) non-red filtered others of said photosensor elements are neighbors of said red filtered photosensor elements and (b) non-red filtered others of said photosensor elements are immediately adjacent to said red filtered photosensor elements.

10. The driver assistance system of claim 1, wherein a green spectral filter is disposed in front of non-red filtered others of said photosensor elements.

11. The driver assistance system of claim 1, wherein a blue spectral filter is disposed in front of non-red filtered others of said photosensor elements.

12. The driver assistance system of claim 1, wherein at least one of (a) identification of objects is based at least in part on the spatial location of objects present in the forward field of view of said imager, (b) said driver assistance system determines an activity level around the equipped vehicle, (c) said driver assistance system determines an environment in which the equipped vehicle is being driven, and (d) said driver assistance system determines an environment in which the equipped vehicle is being driven and said driver assistance system controls a headlight of the equipped vehicle at least in part responsive to said determination of the environment in which the equipped vehicle is being driven.

13. The driver assistance system of claim 1, wherein said driver assistance system is operable to identify lane markers on a road being traveled by the equipped vehicle in order to at least one of (a) assist the driver in steering the equipped vehicle and (b) provide a warning to the driver of the equipped vehicle.

14. The driver assistance system of claim 13, wherein identification of lane markers comprises identification of lane markers by a spectral characteristic.

15. The driver assistance system of claim 1, wherein said driver assistance system is operable to determine atmospheric conditions at the equipped vehicle, and wherein, responsive at least in part to determination of atmospheric conditions, said control is operable to at least one of (i) activate a fog light of the equipped vehicle, (ii) adjust a light beam emitted by a headlight of the equipped vehicle and (iii) inhibit operation of a headlight of the equipped vehicle in a high beam state.

16. The driver assistance system of claim 1, wherein said photosensor array is operable to capture frames of image data and wherein identification of objects is enhanced by comparing image data of objects over successive frames of said captured image data.

17. The driver assistance system of claim 1, wherein identification of objects is based at least in part on at least one of (i) shape, (ii) luminance, (iii) geometry, (iv) spatial location, (v) motion and (vi) spectral characteristic.

18. The driver assistance system of claim 1, wherein said driver assistance system is operable to detect a state of a traffic light and wherein, responsive at least in part to image processing by said image processor detecting a color state of the traffic light, said control at least one of (i) warns the driver of the equipped vehicle, (ii) decelerates the equipped vehicle and (ii) stops the equipped vehicle.

19. The driver assistance system of claim 18, wherein, at least in part responsive to image processing by said image processor, said driver assistance system detects the color state of the traffic light changing from at least one of (i) green to yellow and (ii) yellow to red.

20. The driver assistance system of claim 1, wherein image processing by said image processor of captured image data comprises determination that an object present forward of the equipped vehicle is a stop sign based upon at least one of (i) the object comprising an octagon shape, (ii) the object comprising a red color and (iii) the spatial location of the object in the forward field of view of said imager.

21. The driver assistance system of claim 1, wherein image processing by said image processor of captured image data comprises determination that an object present forward of the equipped vehicle is a caution sign based upon at least one of (i) the object comprising a triangular shape, (ii) the object comprising a yellow color and (iii) the spatial location of the object in the forward field of view of said imager.

22. The driver assistance system of claim 1, wherein said driver assistance system includes an exposure control which determines an accumulation period of time said photosensor array senses light when capturing a frame of image data and wherein said exposure control defines a plurality of accumulation periods.

23. The driver assistance system of claim 22, wherein at least one of (a) said plurality of accumulation periods comprises a first accumulation period for a first frame of captured image data and a second accumulation period for a second frame of captured image data and wherein said first accumulation period is a longer time period than said second accumulation period, (b) said plurality of accumulation periods comprises a first accumulation period for a first frame of captured image data and a second accumulation period for a second frame of captured image data and wherein said first accumulation period is a longer time period than said second accumulation period and wherein said first frame is used when detecting leading vehicle taillights and said second frame is used when detecting approaching vehicle headlights, (c) said exposure control is adaptive and wherein at least one of (i) an accumulation period for a frame of captured image data is set on a priority basis, and (ii) an accumulation period for a frame of captured image data is determined in response to what said driver assistance system is sensing to be present in the forward field of view of said imager, and (d) said exposure control maintains an accumulation period until an object of interest is at least tentatively detected and wherein said exposure control changes to a different accumulation period when an object of interest is at least tentatively detected.

24. The driver assistance system of claim 1, wherein said spectral filter comprises a red/green/blue spectral filter.

25. The driver assistance system of claim 1, comprising an analog-to-digital converter and wherein analog pixel values output by said photosensor array are converted to digital values.

26. The driver assistance system of claim 1, wherein said digital signal processor comprises a microprocessor.

27. The driver assistance system of claim 1, wherein said imager is fixedly mounted in said housing.

28. The driver assistance system of claim 1, wherein said digital signal processor comprises at least one discrete digital circuit module.

29. The driver assistance system of claim 1, wherein said photosensor array is arranged in a matrix of columns of photosensor elements and rows of photosensor elements, and wherein a photosensor element of said photosensor array can be individually accessed via at least one register.

30. The driver assistance system of claim 29, wherein at least one of (i) the number of columns exceeds 512, (ii) the number of rows exceeds 512 and (iii) said photosensor array comprises at least 262,144 photosensor elements.

31. A driver assistance system for a vehicle, said driver assistance system comprising:

a two-dimensional CMOS photosensor array of photosensor elements;

wherein said photosensor array views to the exterior of a vehicle equipped with said driver assistance system, and wherein said photosensor array views through the windshield of the equipped vehicle at a region of the windshield that is swept by a windshield wiper of the equipped vehicle;

wherein said photosensor array is operable to capture image data;

a control comprising an image processor;

wherein said driver assistance system identifies objects viewed by said photosensor array via processing by said image processor of captured image data;

wherein identification of objects is based at least in part on at least one of (i) shape, (ii) luminance, (iii) geometry, (iv) spatial location, (v) motion and (vi) spectral characteristic;

wherein said driver assistance system identifies (a) headlights of approaching vehicles and (b) taillights of leading vehicles; and

wherein said driver assistance system identifies lane markers on a road being traveled by the equipped vehicle.

32. The driver assistance system of claim 31, wherein said driver assistance system identifies lane markers on the road being traveled by the equipped vehicle in order to at least one of (a) assist the driver in steering the equipped vehicle and (b) provide a warning to the driver of the equipped vehicle.

33. The driver assistance system of claim 31, wherein a red spectral filter is disposed in front of some of said photosensor elements and wherein a red spectral filter is not disposed in front of others of said photosensor elements, and wherein at least one of (a) non-red filtered others of said photosensor elements are neighbors of said red filtered photosensor elements and (b) non-red filtered others of said photosensor elements are immediately adjacent to said red filtered photosensor elements.

34. The driver assistance system of claim 31, wherein said photosensor array comprises an array of rows and columns and wherein at least one of (i) the number of columns exceeds 512, (ii) the number of rows exceeds 512 and (iii) said photosensor array comprises at least 262,144 photosensor elements.

35. The driver assistance system of claim 31, wherein said photosensor array is operable to capture frames of image data and wherein identification of objects is enhanced by comparing image data of objects over successive frames of said captured image data.

36. The driver assistance system of claim 31, wherein said photosensor array is operable to capture frames of image data at first and second exposure periods and wherein said first exposure period is shorter than said second exposure period.

37. The driver assistance system of claim 36, wherein said driver assistance system is operable to identify headlights of approaching vehicles responsive to processing of image data captured at said first exposure period and taillights of leading vehicles responsive to processing of image data captured at said second exposure period.

38. The driver assistance system of claim 31, wherein (a) identification of headlights is based at least in part on a spectral characteristic of headlights, and wherein identification of headlights is based at least in part on said control determining that spatially adjacent regions of the forward field of view of said photosensor array include a headlight having a particular spectral characteristic, and (b) identification of taillights is based at least in part on a spectral characteristic of taillights, and wherein identification of taillights is based at least in part on said control determining that spatially adjacent regions of the forward field of view of said photosensor array include a taillight having a particular spectral characteristic.

39. The driver assistance system of claim 31, wherein said control determines if a particular object present forward of the equipped vehicle has a particular spectral characteristic by comparing levels of light sensed by photosensor elements which respond to light in a particular spectral region with levels of light sensed by photosensor elements which respond to light in a different spectral region.

40. The driver assistance system of claim 39, wherein said particular object present forward of the equipped vehicle comprises one of (i) a traffic sign, (ii) a traffic light, (iii) a stop sign and (iv) a caution sign.

41. The driver assistance system of claim 31, wherein at least one of (a) identification of objects is based at least in part on the spatial location of objects present in the forward field of view of said photosensor array, (b) said driver assistance system determines an activity level around the equipped vehicle, (c) said driver assistance system determines an environment in which the equipped vehicle is being driven, and (d) said driver assistance system determines an environment in which the equipped vehicle is being driven and said driver assistance system controls a headlight of the equipped vehicle at least in part responsive to said determination of the environment in which the equipped vehicle is being driven.

42. The driver assistance system of claim 31, wherein said driver assistance system is operable to determine atmospheric conditions at the equipped vehicle, and wherein, responsive at least in part to determination of atmospheric conditions, said control is operable to at least one of (i) activate a fog light of the equipped vehicle, (ii) adjust a light beam emitted by a headlight of the equipped vehicle and (iii) inhibit operation of a headlight of the equipped vehicle in a high beam state.

43. The driver assistance system of claim 31, wherein said control controls a headlight of the equipped vehicle responsive, at least in part, to identification of at least one of (i) a headlight of an approaching vehicle in the forward field of view of said photosensor array and (ii) a taillight of a leading vehicle in the forward field of view of said photosensor array, and wherein said control is operable to at least one of (a) adjust an aim of the headlight of the equipped vehicle, (b) adjust an intensity of the headlight of the equipped vehicle, (c) adjust a pattern of the headlight of the equipped vehicle, (d) switch between a daytime running light condition and another lighting condition, (e) adjust a beam condition of the headlight of the equipped vehicle and (f) adjust a beam of the headlight of the equipped vehicle.

44. The driver assistance system of claim 31, wherein said control at least one of (a) controls a headlight of the equipped vehicle at least in part as a function of a speed of the equipped vehicle, (b) controls a headlight of the equipped vehicle at least in part in response to said image processing, (c) controls a speed of the equipped vehicle at least in part in response to said image processing, (d) generates an alert to the driver of the equipped vehicle responsive at least in part to image processing by said image processor, (e) responsive at least in part to image processing by said image processor, warns the driver of the equipped vehicle, (f) responsive at least in part to image processing by said image processor, decelerates the equipped vehicle, and (g) responsive at least in part to image processing by said image processor, stops the equipped vehicle.

45. The driver assistance system of claim 31, wherein said driver assistance system is operable to detect a state of a traffic light and wherein, responsive at least in part to image processing by said image processor detecting a color state of the traffic light, said control at least one of (i) warns the driver of the equipped vehicle, (ii) decelerates the equipped vehicle and (ii) stops the equipped vehicle.

46. The driver assistance system of claim 45, wherein, at least in part responsive to image processing by said image processor, said driver assistance system detects the color state of the traffic light changing from at least one of (i) green to yellow and (ii) yellow to red.

47. The driver assistance system of claim 31, wherein image processing by said image processor of captured image data comprises determination that an object present forward of the equipped vehicle is a stop sign based upon at least one of (i) the object comprising an octagon shape, (ii) the object comprising a red color and (iii) the spatial location of the object in the forward field of view of said photosensor array.

48. The driver assistance system of claim 31, wherein image processing by said image processor of captured image data comprises determination that an object present forward of the equipped vehicle is a caution sign based upon at least one of (i) the object comprising a triangular shape, (ii) the object comprising a yellow color and (iii) the spatial location of the object in the forward field of view of said photosensor array.

49. The driver assistance system of claim 31, wherein said driver assistance system includes an exposure control which determines an accumulation period of time said photosensor array senses light when capturing a frame of image data and wherein said exposure control defines a plurality of accumulation periods.

50. The driver assistance system of claim 49, wherein at least one of (a) said plurality of accumulation periods comprises a first accumulation period for a first frame of captured image data and a second accumulation period for a second frame of captured image data and wherein said first accumulation period is a longer time period than said second accumulation period, (b) said plurality of accumulation periods comprises a first accumulation period for a first frame of captured image data and a second accumulation period for a second frame of captured image data and wherein said first accumulation period is a longer time period than said second accumulation period and wherein said first frame is used when detecting leading vehicle taillights and said second frame is used when detecting approaching vehicle headlights, (c) said exposure control is adaptive and wherein at least one of (i) an accumulation period for a frame of captured image data is set on a priority basis, and (ii) an accumulation period for a frame of captured image data is determined in response to what said driver assistance system is sensing to be present in the forward field of view of said photosensor array, and (d) said exposure control maintains an accumulation period until an object of interest is at least tentatively detected and wherein said exposure control changes to a different accumulation period when an object of interest is at least tentatively detected.

51. The driver assistance system of claim 31, wherein said photosensor array comprises at least 262,144 photosensor elements.

52. The driver assistance system of claim 31, wherein said photosensor array comprises an array of rows and columns and wherein at least one of (i) the number of columns exceeds 512, (ii) the number of rows exceeds 512 and (iii) said photosensor array comprises at least 262,144 photosensor elements.

53. The driver assistance system of claim 31, wherein said photosensor array, a lens and a spectral filter are disposed in a housing.

54. The driver assistance system of claim 53, wherein said housing mounts via a bracket at the vehicle windshield.

55. The driver assistance system of claim 54, wherein said photosensor array is operable to capture frames of image data and wherein identification of objects is enhanced by comparing image data of objects over successive frames of said captured image data.

56. The driver assistance system of claim 53, wherein said lens comprises a plastic lens.

57. The driver assistance system of claim 53, wherein at least one of (a) said spectral filter attenuates light having a wavelength greater than about 830 nanometers and wherein light emitted by sources external of the equipped vehicle and/or reflected by objects external of the equipped vehicle is filtered by said spectral filter to be incident on said photosensor array, (b) said spectral filter comprises a red filter that passes visible light of wavelength generally in the red portion of the visible spectrum and that attenuates light having wavelengths generally outside the red portion of the visible spectrum, and (c) said spectral filter comprises a red complement filter that substantially passes wavelengths generally outside the red portion of the visible spectrum and that attenuates wavelengths generally outside the red portion of the visible spectrum.

58. The driver assistance system of claim 53, wherein said image processor comprises a digital signal processor.

59. The driver assistance system of claim 58, wherein said digital signal processor is disposed in said housing.

60. The driver assistance system of claim 31, wherein said driver assistance system discriminates at least one of (i) headlights of approaching vehicles from streetlights and (ii) taillights of leading vehicles from streetlights.

61. The driver assistance system of claim 31, wherein said driver assistance system discriminates at least one of (i) headlights of approaching vehicles from reflections off signs of light emitted by the equipped vehicle'"'"'s headlights and (ii) taillights of leading vehicles from reflections off signs of light emitted by the equipped vehicle'"'"'s headlights.

62. The driver assistance system of claim 31, wherein said photosensor array is arranged in a matrix of columns of photosensor elements and rows of photosensor elements, and wherein a photosensor element of said photosensor array can be individually accessed via at least one register, and wherein at least one of (i) the number of columns exceeds 512, (ii) the number of rows exceeds 512 and (iii) said photosensor array comprises at least 262,144 photosensor elements.

63. A driver assistance system for a vehicle, said driver assistance system comprising:

a two-dimensional CMOS photosensor array of photosensor elements;

wherein said photosensor array views to the exterior of a vehicle equipped with said driver assistance system, and wherein said photosensor array views through the windshield of the equipped vehicle at a region of the windshield that is swept by a windshield wiper of the equipped vehicle;

wherein said photosensor array is operable to capture image data;

a control comprising an image processor;

wherein said driver assistance system identifies objects viewed by said photosensor array via processing by said image processor of captured image data;

wherein a red spectral filter is disposed in front of some of said photosensor elements and wherein a red spectral filter is not disposed in front of others of said photosensor elements; and

wherein said photosensor array comprises at least 262,144 photosensor elements.

64. The driver assistance system of claim 63, wherein said red spectral filter is disposed between a lens and said photosensor array.

65. The driver assistance system of claim 63, wherein said photosensor array is accommodated in a body at the in-cabin surface of the windshield of the equipped vehicle.

66. The driver assistance system of claim 65, wherein said body accommodates said image processor.

67. The driver assistance system of claim 63, wherein a green spectral filter is disposed in front of non-red filtered others of said photosensor elements.

68. The driver assistance system of claim 63, wherein a blue spectral filter is disposed in front of non-red filtered others of said photosensor elements.

69. The driver assistance system of claim 63, wherein at least one of (a) identification of objects is based at least in part on the spatial location of objects present in the forward field of view of said photosensor array, (b) said driver assistance system determines an activity level around the equipped vehicle, (c) said driver assistance system determines an environment in which the equipped vehicle is being driven, and (d) said driver assistance system determines an environment in which the equipped vehicle is being driven and said driver assistance system controls a headlight of the equipped vehicle at least in part responsive to said determination of the environment in which the equipped vehicle is being driven.

70. The driver assistance system of claim 63, wherein said driver assistance system is operable to identify lane markers on a road being traveled by the equipped vehicle in order to at least one of (a) assist the driver in steering the equipped vehicle and (b) provide a warning to the driver of the equipped vehicle.

71. The driver assistance system of claim 70, wherein, and identification of lane markers comprises identification of lane markers by a spectral characteristic.

72. The driver assistance system of claim 63, wherein said driver assistance system is operable to determine atmospheric conditions at the equipped vehicle, and wherein, responsive at least in part to determination of atmospheric conditions, said control is operable to at least one of (i) activate a fog light of the equipped vehicle, (ii) adjust a light beam emitted by a headlight of the equipped vehicle and (iii) inhibit operation of a headlight of the equipped vehicle in a high beam state.

73. The driver assistance system of claim 63, wherein said photosensor array is operable to capture frames of image data and wherein identification of objects is enhanced by comparing image data of objects over successive frames of said captured image data.

74. The driver assistance system of claim 63, wherein identification of objects is based at least in part on at least one of (i) shape, (ii) luminance, (iii) geometry, (iv) spatial location, (v) motion and (vi) spectral characteristic.

75. The driver assistance system of claim 63, wherein said driver assistance system is operable to detect a state of a traffic light and wherein, responsive at least in part to image processing by said image processor detecting a color state of the traffic light, said control at least one of (i) warns the driver of the equipped vehicle, (ii) decelerates the equipped vehicle and (ii) stops the equipped vehicle.

76. The driver assistance system of claim 75, wherein, at least in part responsive to image processing by said image processor, said driver assistance system detects the color state of the traffic light changing from at least one of (i) green to yellow and (ii) yellow to red.

77. The driver assistance system of claim 63, wherein image processing by said image processor of captured image data comprises determination that an object present forward of the equipped vehicle is a stop sign based upon at least one of (i) the object comprising an octagon shape, (ii) the object comprising a red color and (iii) the spatial location of the object in the forward field of view of said photosensor array.

78. The driver assistance system of claim 63, wherein image processing by said image processor of captured image data comprises determination that an object present forward of the equipped vehicle is a caution sign based upon at least one of (i) the object comprising a triangular shape, (ii) the object comprising a yellow color and (iii) the spatial location of the object in the forward field of view of said photosensor array.

79. The driver assistance system of claim 63, wherein said driver assistance system includes an exposure control which determines an accumulation period of time said photosensor array senses light when capturing a frame of image data and wherein said exposure control defines a plurality of accumulation periods.

80. The driver assistance system of claim 79, wherein at least one of (a) said plurality of accumulation periods comprises a first accumulation period for a first frame of captured image data and a second accumulation period for a second frame of captured image data and wherein said first accumulation period is a longer time period than said second accumulation period, (b) said plurality of accumulation periods comprises a first accumulation period for a first frame of captured image data and a second accumulation period for a second frame of captured image data and wherein said first accumulation period is a longer time period than said second accumulation period and wherein said first frame is used when detecting leading vehicle taillights and said second frame is used when detecting approaching vehicle headlights, (c) said exposure control is adaptive and wherein at least one of (i) an accumulation period for a frame of captured image data is set on a priority basis, and (ii) an accumulation period for a frame of captured image data is determined in response to what said driver assistance system is sensing to be present in the forward field of view of said photosensor array, and (d) said exposure control maintains an accumulation period until an object of interest is at least tentatively detected and wherein said exposure control changes to a different accumulation period when an object of interest is at least tentatively detected.

81. The driver assistance system of claim 63, wherein said photosensor array is arranged in a matrix of columns of photosensor elements and rows of photosensor elements, and wherein a photosensor element of said photosensor array can be individually accessed via at least one register, and wherein at least one of (i) the number of columns exceeds 512 and (ii) the number of rows exceeds 512.

82. A driver assistance system for a vehicle, said driver assistance system comprising:

a two-dimensional CMOS photosensor array of photosensor elements;

wherein said photosensor array views to the exterior of a vehicle equipped with said driver assistance system, and wherein said photosensor array views through the windshield of the equipped vehicle at a region of the windshield that is swept by a windshield wiper of the equipped vehicle;

wherein said photosensor array is operable to capture image data;

a control comprising an image processor;

wherein said driver assistance system identifies objects viewed by said photosensor array via processing by said image processor of captured image data;

wherein said photosensor array comprises at least 262,144 photosensor elements;

wherein a spectral filter is disposed between said photosensor array and a lens;

wherein said photosensor array, said lens and said spectral filter are disposed in a housing that mounts via a bracket at the vehicle windshield; and

wherein objects identified present forward of the equipped vehicle comprise at least one of (i) approaching headlights, (ii) leading taillights, (iii) lane markers, (iv) traffic signs, (v) traffic lights, (vi) stop signs and (vii) caution signs.

83. The driver assistance system of claim 82, wherein said driver assistance system is operable to identify lane markers on a road being traveled by the equipped vehicle in order to at least one of (a) assist the driver in steering the equipped vehicle and (b) provide a warning to the driver of the equipped vehicle.

84. The driver assistance system of claim 83, wherein identification of lane markers comprises identification of lane markers by a spectral characteristic.

85. The driver assistance system of claim 82, wherein a red spectral filter is disposed in front of some of said photosensor elements and wherein a red spectral filter is not disposed in front of others of said photosensor elements.

86. The driver assistance system of claim 85, wherein said control controls a headlight of the equipped vehicle responsive, at least in part, to identification of at least one of (i) a headlight of an approaching vehicle in the forward field of view of said photosensor array and (ii) a taillight of a leading vehicle in the forward field of view of said photosensor array, and wherein said control is operable to at least one of (a) adjust an aim of the headlight of the equipped vehicle, (b) adjust an intensity of the headlight of the equipped vehicle, (c) adjust a pattern of the headlight of the equipped vehicle, (d) switch between a daytime running light condition and another lighting condition, (e) adjust a beam condition of the headlight of the equipped vehicle and (f) adjust a beam of the headlight of the equipped vehicle.

87. The driver assistance system of claim 86, wherein said driver assistance system is operable to determine atmospheric conditions at the equipped vehicle, and wherein, responsive at least in part to determination of atmospheric conditions, said control is operable to at least one of (i) activate a fog light of the equipped vehicle, (ii) adjust a light beam emitted by a headlight of the equipped vehicle and (iii) inhibit operation of a headlight of the equipped vehicle in a high beam state.

88. The driver assistance system of claim 82, wherein said photosensor array is operable to capture frames of image data at first and second exposure periods and wherein said first exposure period is shorter than said second exposure period.

89. The driver assistance system of claim 82, wherein said photosensor array is arranged in a matrix of columns of photosensor elements and rows of photosensor elements, and wherein a photosensor element of said photosensor array can be individually accessed via at least one register, and wherein at least one of (i) the number of columns exceeds 512 and (ii) the number of rows exceeds 512.

90. The driver assistance system of claim 89, comprising an analog-to-digital converter and wherein analog pixel values output by said photosensor array are converted to digital values, and wherein said image processor comprises a microprocessor.

91. The driver assistance system of claim 82, wherein at least one of (a) said spectral filter attenuates light having a wavelength greater than about 830 nanometers and wherein light emitted by sources external of the equipped vehicle and/or reflected by objects external of the equipped vehicle is filtered by said spectral filter to be incident on said photosensor array, (b) said spectral filter comprises a red filter that passes visible light of wavelength generally in the red portion of the visible spectrum and that attenuates light having wavelengths generally outside the red portion of the visible spectrum, and (c) said spectral filter comprises a red complement filter that substantially passes wavelengths generally outside the red portion of the visible spectrum and that attenuates wavelengths generally outside the red portion of the visible spectrum.

92. The driver assistance system of claim 82, wherein said control at least one of (a) controls a headlight of the equipped vehicle at least in part as a function of a speed of the equipped vehicle, (b) controls a headlight of the equipped vehicle at least in part in response to said image processing, (c) controls a speed of the equipped vehicle at least in part in response to said image processing, (d) generates an alert to the driver of the equipped vehicle responsive at least in part to image processing by said image processor, (e) responsive at least in part to image processing by said image processor, warns the driver of the equipped vehicle, (f) responsive at least in part to image processing by said image processor, decelerates the equipped vehicle, and (g) responsive at least in part to image processing by said image processor, stops the equipped vehicle.

93. The driver assistance system of claim 82, wherein said driver assistance system is operable to detect a state of a traffic light and wherein, responsive at least in part to image processing by said image processor detecting a color state of the traffic light, said control at least one of (i) warns the driver of the equipped vehicle, (ii) decelerates the equipped vehicle and (iii) stops the equipped vehicle.

94. The driver assistance system of claim 82, wherein at least one of (a) image processing by said image processor of captured image data comprises determination that an object present forward of the equipped vehicle is a stop sign based upon at least one of (i) the object comprising an octagon shape, (ii) the object comprising a red color and (iii) the spatial location of the object in the forward field of view of said photosensor array and (b) image processing by said image processor of captured image data comprises determination that an object present forward of the equipped vehicle is a caution sign based upon at least one of (i) the object comprising a triangular shape, (ii) the object comprising a yellow color and (iii) the spatial location of the object in the forward field of view of said photosensor array.

95. A driver assistance system for a vehicle, said driver assistance system comprising:

a two-dimensional CMOS photosensor array of photosensor elements;

wherein said photosensor array views to the exterior of a vehicle equipped with said driver assistance system, and wherein said photosensor array views through the windshield of the equipped vehicle at a region of the windshield that is swept by a windshield wiper of the equipped vehicle;

wherein said photosensor array is operable to capture image data;

a control comprising an image processor;

wherein said driver assistance system identifies objects viewed by said photosensor array via processing by said image processor of captured image data;

wherein said photosensor array comprises at least 262,144 photosensor elements; and

wherein said photosensor array is arranged in a matrix of columns of photosensor elements and rows of photosensor elements, and wherein at least one of (i) the number of columns exceeds 512 and (ii) the number of rows exceeds 512.

96. The driver assistance system of claim 95, comprising an analog-to-digital converter and wherein analog pixel values output by said photosensor array are converted to digital values, and wherein said image processor comprises a microprocessor.

97. The driver assistance system of claim 95, wherein a spectral filter is disposed between said photosensor array and a lens and wherein said photosensor array, said lens and said spectral filter are disposed in a housing that mounts via a bracket at the vehicle windshield.

98. The driver assistance system of claim 97, wherein objects identified present forward of the equipped vehicle comprise at least one of (i) approaching headlights, (ii) leading taillights, (iii) lane markers, (iv) traffic signs, (v) traffic lights, (vi) stop signs and (vii) caution signs.

99. The driver assistance system of claim 97, wherein said bracket comprises part of an interior rearview mirror system of the equipped vehicle.

100. The driver assistance system of claim 95, wherein said driver assistance system is operable to identify lane markers on a road being traveled by the equipped vehicle in order to at least one of (a) assist the driver in steering the equipped vehicle and (b) provide a warning to the driver of the equipped vehicle

101. The driver assistance system of claim 95, wherein identification of lane markers comprises identification of lane markers by a spectral characteristic.

102. The driver assistance system of claim 95, wherein a red spectral filter is disposed in front of some of said photosensor elements and wherein a red spectral filter is not disposed in front of others of said photosensor elements.

103. The driver assistance system of claim 102, wherein said control controls a headlight of the equipped vehicle responsive, at least in part, to identification of at least one of (i) a headlight of an approaching vehicle in the forward field of view of said photosensor array and (ii) a taillight of a leading vehicle in the forward field of view of said photosensor array, and wherein said control is operable to at least one of (a) adjust an aim of the headlight of the equipped vehicle, (b) adjust an intensity of the headlight of the equipped vehicle, (c) adjust a pattern of the headlight of the equipped vehicle, (d) switch between a daytime running light condition and another lighting condition, (e) adjust a beam condition of the headlight of the equipped vehicle and (f) adjust a beam of the headlight of the equipped vehicle.

104. The driver assistance system of claim 103, wherein said driver assistance system is operable to identify lane markers on a road being traveled by the equipped vehicle.

105. The driver assistance system of claim 103, wherein said spectral filter attenuates light having a wavelength greater than about 830 nanometers and wherein light emitted by sources external of the equipped vehicle and/or reflected by objects external of the equipped vehicle is filtered by said spectral filter to be incident on said photosensor array.

106. The driver assistance system of claim 95, and wherein a photosensor element of said photosensor array can be individually accessed by a register.

107. The driver assistance system of claim 106, wherein said photosensor element of said photosensor array can be individually accessed via a horizontal shift register and a vertical shift register.