Night-vision image processing apparatus

• US 10,063,788 B2
• Filed: 02/06/2014
• Issued: 08/28/2018
• Est. Priority Date: 02/08/2013
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Hattori, Kazushige, Suzuki, Hirotaka, Inoue, Nobuhiko, Ohta, Kazuhide
• Primary Examiner(s): Ren, Zhubing
• Application Number:
  US14/766,113
• Publication Number:
  US 20150373278A1
• Time in Patent Office: 1,664 Days
• CPC Class Codes: B60R 1/30 providing vision in the non-visible spectrum, e.g. night or infrared vision
• CPC Class Codes: G02B 5/20 Filters polarising elements G02B5/30
• CPC Class Codes: G02B 5/208 for use with infrared or ultraviolet radiation, e.g. for separating visible light from infrared and/or ultraviolet radiation
• CPC Class Codes: G08G 1/166 for active traffic, e.g. moving vehicles, pedestrians, bikes
• CPC Class Codes: H04N 23/11 for generating image signals from visible and infrared light wavelengths
• CPC Class Codes: H04N 23/76 by influencing the image signals
• CPC Class Codes: H04N 23/81 for suppressing or minimising disturbance in the image signal generation
• CPC Class Codes: H04N 25/131 including elements passing infrared wavelengths
• CPC Class Codes: H04N 25/135 based on four or more different wavelength filter elements

Abstract

An image processing apparatus includes an image acquirement section, a correction section, and an image production section. The image acquirement section acquires an image signal representing an image, the image signal is generated by light receiving elements that receive lights from a specific space preliminarily defined in a vicinity of a vehicle via a near infrared passing filter mainly transmitting near infrared lights and a visible light passing filter transmitting visible lights and near infrared lights, respectively. The image includes multiple areas and indicates the specific space projected onto a plane. The correction section corrects each area of the image by amplifying intensity of near infrared lights with an increasing amplification factor when a difference between the intensity of near infrared lights and intensity of visible lights and near infrared lights becomes smaller. The image production section produces a new image based on the corrected areas of the image.

Claims

1. An image processing apparatus comprising:

an image acquirement section acquiring, using a processor, an image signal representing an image, wherein the image signal is generated by a light receiving element that receives lights coming from a specific space via a near infrared passing filter and a light receiving element that receives the lights coming from the specific space via a visible light passing filter, the specific space is provided by a spatial area that is preliminarily defined in a vicinity of a vehicle, the near infrared passing filter mainly transmits near infrared lights and the visible light passing filter transmits visible lights and the near infrared lights, the visible lights have respective wavelengths that fall within a visible wavelength range, and the image acquired by the image acquirement section includes a plurality of areas and indicates the specific space projected onto a plane;

a correction section correcting, using the processor, a subject area that is defined as one of the plurality of areas included in the image by amplifying an intensity of the near infrared lights in the subject area with an increasing amplification factor when determining that a difference between the intensity of the near infrared lights and an intensity of the lights including the visible lights and the near infrared lights in the subject area becomes smaller, wherein the correction section corrects each of the plurality of areas included in the image;

an image production section producing, using the processor, a new image based on the plurality of areas corrected by the correction section; and

wherein when correcting the intensity of the near infrared lights in the subject area, the correction section multiplies the intensity of the near infrared lights by the amplification factor, and the amplification factor is a coefficient that increases with a decrease of the difference between the intensity of the near infrared lights and the intensity of the lights including the visible lights and the near infrared lights.

2. The image processing apparatus according to claim 1, wherein

the light receiving element that receives the lights coming from the specific space via the visible light passing filter is provided by one of a first light receiving element, a second light receiving element, or a third light receiving element,

the first light receiving element receives the lights coming from the specific space via a red filter that mainly transmits the near infrared lights and the lights having wavelengths of red lights,

the second light receiving element receives the lights coming from the specific space via a green filter that mainly transmits the near infrared lights and the lights having wavelengths of green lights,

the third light receiving element receives the lights coming from the specific space via a blue filter that mainly transmits the near infrared lights and the lights having wavelengths of blue lights, and each of the red light, the green light, and the blue light is one of three primary colors of light, and

the intensity of the lights including the visible lights and the near infrared lights includes the intensity of the near infrared lights and an intensity of the visible lights, which are at least one of red lights, green lights, or blue lights, and the red light, the green light, and the blue light configure the three primary colors of light.

3. An image processing apparatus comprising:

an image acquirement section acquiring, using the processor, an image signal representing an image, wherein the image signal is generated by a light receiving element that receives lights coming from a specific space via a near infrared passing filter and a light receiving element that receives the lights coming from the specific space via a visible light passing filter, the specific space is provided by a spatial area that is preliminarily defined in a vicinity of a vehicle, the near infrared passing filter mainly transmits near infrared lights and the visible light passing filter transmits visible lights and the near infrared lights, the visible lights have respective wavelengths that fall within a visible wavelength range, and the image acquired by the image acquirement section includes a plurality of areas and indicates the specific space projected onto a plane;

a correction section correcting, using the processor, a subject area that is defined as one of the plurality of areas included in the image by amplifying an intensity of the near infrared lights in the subject area with an increasing amplification factor when determining that a ratio of an intensity of the lights including the visible lights and the near infrared lights to the intensity of the near infrared lights in the subject area becomes smaller, wherein the correction section corrects each of the plurality of areas included in the image;

an image production section producing, using the processor, a new image based on the plurality of areas corrected by the correction section; and

wherein, when correcting the intensity of the near infrared lights in the subject area, the correction section multiplies the intensity of the near infrared lights by the amplification factor, and the amplification factor is a coefficient that increases with a decrease of the ratio of the intensity of the lights including the visible lights and the near infrared lights to the intensity of the near infrared lights.

4. The image processing apparatus according to claim 3, wherein

the light receiving element that receives the lights coming from the specific space via the visible light passing filter is provided by one of a first light receiving element, a second light receiving element, or a third light receiving element,

the first light receiving element receives the lights coming from the specific space via a red filter that mainly transmits the near infrared lights and the lights having wavelengths of red lights,

the second light receiving element receives the lights coming from the specific space via a green filter that mainly transmits the near infrared lights and the lights having wavelengths of green lights,

the third light receiving element receives the lights coming from the specific space via a blue filter that mainly transmits the near infrared lights and the lights having wavelengths of blue lights, and each of the red light, the green light, and the blue light is one of three primary colors of light, and

the intensity of the lights including the visible lights and the near infrared lights includes the intensity of the near infrared lights and an intensity of the visible lights, which are at least one of red lights, green lights, or blue lights, and the red light, the green light, and the blue light configure the three primary colors of light.