JP2001285678A - Two-image simultaneous pickup processing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a two-image simultaneous pickup processing apparatus that can pick up two images on one image pickup face while distinguishing them. SOLUTION: A light passing through a lens 10 reaches an image pickup face 41 through a wavelength selection filter 20 having a pass band equivalent to a wavelength not passing through an 'R' filter, and a light passing through a lens 11 reaches the same image pickup face 41 through a wavelength selection filter 21 having a pass band equivalent to a wavelength not passing through an 'B' filter, and a color electronic camera 40 outputs two output signals; 'B' and 'R' signals. Through the configuration above, one image pickup face of the single color electronic camera can pick up two images separately and process the respective images independently. Thus, problems of an optical system, high cost, a large-scale, and increase in the weight or the like are not caused different from the provision of two cameras and the single camera can process two images.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-screen simultaneous image processing apparatus for picking up two images on one image pickup surface while distinguishing them, and is applied to, for example, detection of a white line of a vehicle, detection of a road surface condition, a blind monitor and the like. It is.

[0002]

2. Description of the Related Art In recent years, for automatic driving and driving assistance of a vehicle, an image of a vehicle-mounted camera has been processed to detect a white line and to extract a preceding vehicle. In such image processing, it is necessary to take a road image irrespective of brightness, even when there is a large difference in illuminance on a road surface such as a shadow of a building or an entrance of a tunnel. However, the dynamic range required in the above road environment is about 100 d.
In contrast to b, the dynamic range of the conventional CCD image pickup device is 40 to 60 db, and at present, it is significantly small. A conventional method for obtaining a wide dynamic range image is disclosed in Japanese Patent Application Laid-Open No. 6-105224. In this method, light passing through one lens is divided into two by a light distributor, and each is captured by an electronic camera with a shutter, and on the one hand, a dark portion such as a shadow is captured, and on the other hand, a bright portion which is not a shadow is captured. Is taken, and these two images are combined.

[0003]

However, in such a method, the first problem is that two components are displaced due to the misalignment of the optical components and the imaging surface in the two optical paths and the difference in distortion of the optical components themselves. Since a relative shift occurs due to the distortion in the captured image, it is necessary to process the light distributor and to arrange the optical components and the imaging surfaces of the two optical systems with high accuracy, which is costly. The second problem is that the use of a light distributor and two cameras increases the physical size and weight. Further, if a road condition such as a puddle can be detected by image processing, or if a plurality of images in different directions can be separated and obtained by one camera, the application range of the image processing device for a vehicle can be expanded. However, there was no such device.

SUMMARY OF THE INVENTION The present invention has been made to solve the problems of the prior art as described above, and has as its object to provide a two-screen simultaneous imaging processing apparatus for separately imaging two images on one imaging surface. I do.

[0005]

In order to achieve the above object, the present invention is configured as described in the appended claims. That is, according to the first aspect of the invention, a wavelength selection filter having a different transmission wavelength band is provided for each of the two lenses, and an image formed through the two lenses is formed on one imaging surface of one color electronic camera. It is configured to take an image, separately output two electric signals corresponding to the respective transmission wavelength bands, and process the two electric signals. With such a configuration, two images can be separated and captured separately on one imaging surface of one color electronic camera, and each image can be processed independently. Therefore, as in the case where two cameras are provided, problems with the optical system, cost increase,
It is possible to perform two image processings with one camera without causing problems such as an increase in size and an increase in weight.

The second aspect of the present invention is directed to a configuration for coping with a case where there is an area having a large difference in luminance in an image pickup screen. Both the first and second lens systems have different attenuation rates. Either a filter is added or an attenuation filter is added to only one lens system. In this configuration, it is possible to obtain a clear image by separating the image of the region with high luminance from the image of the region with low luminance, and outputting as two clear image signals regardless of the luminance level. As a result, a wide dynamic range for luminance can be realized. Each of the above image signals can be subjected to image processing, and by combining the two, the entire image can be clearly reproduced. Therefore, if the present invention is applied to a white line detection device using an in-vehicle camera, accurate image processing can be performed regardless of brightness even when the difference in illuminance on the road surface is large.

A third aspect of the present invention is a specific example of the first or second aspect, wherein the first wavelength selection filter has a transmission band of a wavelength that does not transmit the “R” filter, and The wavelength selection filter has a transmission band of a wavelength that does not transmit the “B” filter, and outputs a “B” signal and an “R” signal of a color signal as two output signals of the color electronic camera.

The invention according to claim 4 relates to a configuration for detecting a puddle or the like on a road surface, wherein a polarizing filter is added to a first lens system, and an attenuation filter is provided to a second lens system. 2 output from the color electronic camera
By obtaining the difference between the two images, the polarization region on the imaging screen is detected. Since no polarization occurs on a dry road surface, the value of the difference is small, whereas on a wet road surface, the reflected light from the water film is polarized, and this portion is removed by a polarizing filter. Increases, resulting in polarization regions (wet road surfaces, puddles, etc.)
Can be detected.

The invention according to claim 5 is applied to a so-called blind monitor. A mirror is provided in front of the first and second lenses, and left and right scenes having different angles are incident on the respective lenses. Two black-and-white monitors that respectively display two image signals output from the color electronic camera as images, or a unit that performs obstacle detection image processing on the two image signals, respectively. It is a thing. In the present invention, 2
Two images can be separated and processed, so if a mirror is provided in front of the lens and left and right images are input,
One image can be processed by one camera, and each image can be displayed on two monitor screens, or an obstacle detection process can be performed separately. For example, if a mirror is provided at the front end of the vehicle and the mirror advances to a position where the left and right road images can be captured at an intersection or the like, the situation of the left and right roads that cannot be seen from the driver's seat can be visually recognized on the two monochrome monitor screens can do. Further, if the obstacle detection processing is performed for each image signal, obstacles on the left and right roads can be detected.

[0010]

According to the first aspect of the present invention, it is preferable that two
Since two images are imaged, the directions of the imaging surfaces of the two images with respect to the subject are uniform, and the optical component is only a lens, so that the deviation due to the relative distortion difference between the two images is reduced. If the lens is a pinhole, the optical distortion is further reduced. Further, since the images are separated according to the wavelength of light, the images of the two lenses can be superimposed. Therefore, it is possible to reduce the size by bringing the lenses closer. If the lens is a pinhole, it can be made very small. Further, as described above, since the two images can be superimposed, the entire surface can be used without dividing the imaging surface, so that an image with a wider angle or higher resolution can be obtained than in the case of dividing. can get.

According to the second aspect of the present invention, an image in an area with a high luminance and an image in an area with a low luminance can be separated from each other, and can be extracted as two clear image signals regardless of the magnitude of the luminance. Each of them can be subjected to image processing, and by combining them, the entire image can be reproduced clearly. Therefore, if the present invention is applied to a white line detection device using an in-vehicle camera, accurate image processing can be performed regardless of brightness even when the illuminance difference on the road surface is large, and a wide dynamic range can be realized.

According to the third aspect of the present invention, the output of the "B" signal and the "R" signal of the color signal using a normal color electronic camera can realize a simple and inexpensive configuration. According to the fourth aspect, since a polarized region such as a wet road surface or a puddle can be detected, it is possible to prevent erroneous detection with a white line and to improve accuracy of control of avoiding a puddle in an automatic steering device. Can be. According to the fifth aspect, it is possible to reliably detect an obstacle at a location that cannot be seen from the driver's seat.

[0013]

FIG. 1 is a block diagram showing first and second embodiments of the present invention. In FIG. 1, two lenses 10 and 11 are arranged in a lens case 30 made of a light shielding member, and an optical filter 50 (described in detail later) and a wavelength selection filter 20 are arranged in an optical path of the lens 10.
The optical filter 51 and the wavelength selection filter 21 are arranged on the optical path of the lens 11. The respective lights passing through the lenses 10 and 11 form the image on the imaging surface 41 of the color electronic camera 40 after passing through the respective filter groups.

The color electronic camera 40 detects the intensity of light of each wavelength through color filters of three primary colors "R", "G", and "B" of light.
Transmits wavelength components that do not pass through the color filter “B” of the color electronic camera 40, and the wavelength selection filter 21 transmits wavelength components that do not pass through the color filter “R” of the color electronic camera 40. Therefore, the image formed by the lens 10 is mainly captured by the image sensor having the color filter “R”, and the video signal is output from the “R” output of the color electronic camera 40. The image from the lens 11 is mainly captured by an image sensor having a color filter “B”, and the video signal is output from the “B” output of the electronic camera.

FIG. 2 is a characteristic diagram showing the relative sensitivities of the color filters and the wavelength selection filters 20 and 21 of the color electronic camera. In FIG. 2, "R", "G", and "B" indicate characteristics of each color filter of the color electronic camera. By setting the characteristics of the two wavelength selection filters to the characteristics shown in FIG. 2, the two images can be output as “B” and “R” signals, respectively, as described above.
Although it is possible to divide the data into "R" and "G" or "B" and "G", as can be seen from the characteristics of FIG.
Since the wavelengths of “R” and “R” are far from each other, separation is easy.
Further, as shown in FIG. 2, the wavelength selection filter 20 does not transmit the "B" and "G" wavelength regions, and the wavelength selection filter 21 does not transmit the "G" and "R" wavelength regions. That is, it is only necessary to have a characteristic of transmitting only a necessary wavelength region.

An optical filter 50 is provided in an optical path passing through the lens 10 and forming an image on the imaging surface. An optical filter 51 is provided in an optical path passing through the lens 11 and forming an image on the imaging surface.
There is. The following functions can be realized by the functions of the optical filters 50 and 51 and the method of calculating the two video outputs “R” and “B” in the image processing unit 60.

First, as a first embodiment, an example will be described in which an image in an area with a high luminance and an image in an area with a low luminance are respectively captured, and a clear image signal is output regardless of the luminance level. In this case, the optical filter 50 and the optical filter 51 are used as attenuation filters, and the optical filter 50 is used.
Is made smaller than that of the optical filter 51.

Hereinafter, the processing in the image processing unit 60 will be described based on the processing flow shown in FIG. First, in step S10, two image signals "R" and "B" output from the color electronic camera 40 are input and stored in the memory. Next, in step S11, parallel movement correction for aligning the two images is performed. For this, the same subject is imaged in advance, the direction and magnitude of the parallel movement of the two images are measured, and the values are used as correction values.
Next, in step S12, by combining the two images, the image captured on the dark side by the lens 20 and the lens 2
In step 1, two images of the bright side are combined. With these processes, a clear image can be obtained regardless of the magnitude of the luminance of the subject, and a wide dynamic range with respect to the luminance can be realized. After that, step S
At 13, white line detection and obstacle (eg, preceding vehicle) detection processing are performed on the image. This makes it possible to perform white line detection and vehicle detection in front of the vehicle without generating an image-impossible portion due to a difference in brightness between a tunnel entrance and a sunshine or shade.

Next, as a second embodiment, an example of detecting a wet road surface, a puddle or the like will be described. In this case, the optical filter 50 is a polarization filter, and the optical filter 51 is an attenuation filter having an attenuation rate equivalent to that of the polarization filter.
The reason why the attenuation rate of the attenuation filter is made equal to that of the polarization filter is to make the operation in the electronic circuit of the color electronic camera 40 equal by adjusting the approximate signal levels of “R” and “B” of the image sensor. It is.

Hereinafter, the processing in the image processing unit 60 will be described based on the processing flow shown in FIG. First, in step S20, two image signals "R" and "B" output from the color electronic camera 40 are input and stored in the memory. Next, in step S21, as in the process of step S11 in FIG. 3, parallel movement correction for aligning the two images is performed. In step S22, density conversion is performed. That is, an image of the same subject that does not produce polarized light is taken, and the unpolarized portions of the two images have the same density.
Density correction is performed using a density conversion table created in advance. In step S23, the difference between the two images after the density correction is calculated. And in step S24,
The polarization region (water film region) is detected by comparing with a preset threshold th. Since no polarization occurs on a dry road surface, there is no difference in density between the two images, and thus the value of the difference is small. On the other hand, on a wet road surface or a road surface with a puddle of water, the reflected light from the water film portion is polarized, so it is cut by the polarizing filter, and a density difference occurs between the water film portions of the two images.
The value of the difference in that area increases. Therefore, by comparing the difference image with a preset threshold th,
A region having a large difference can be detected as a water film region. The detection of the water film region as described above can be used for preventing a water pool from being erroneously detected as a white line in a system that performs white line detection by image processing, avoiding the water pool region by automatic steering, and controlling deceleration passage by automatic braking. .

FIG. 5 is a block diagram showing a third embodiment of the present invention. This embodiment constitutes a so-called blind monitor. As shown in FIG. 5, a mirror 70 is provided in front of the lenses 10 and 11, so that the left and right scenes are input through separate lenses. In FIG. 5, the mirror 70 is bent at a right angle so that the right and left directions are photographed. However, depending on the angle of the mirror 70, it may be set so that the left and right sides are photographed slightly forward and backward. The filters provided after the lenses 10 and 11 are wavelength selection filters 20 and
21 only, and the optical filters 50 and 51 are not used.

In the apparatus shown in FIG. 5, a scene incident on the lens 10 (eg, a right scene) is output as an “R” signal, and a scene incident on the lens 11 (eg, a left scene).
Are output as "B" signals. Therefore, each signal is converted to a black and white monitor (for example, a liquid crystal display,
(RT display devices) 80 and 81 to display the left and right scenes independently. Alternatively, if an obstacle detection device based on image processing is connected instead of the black and white monitors 80 and 81, obstacle detection processing can be performed in both the left and right directions. For example, a mirror 70 is provided at the tip of the vehicle.
If the mirror 70 advances to a position where the left and right road images can be captured at an intersection or the like, the situation of the left and right roads that cannot be seen from the driver's seat can be visually recognized on the two black and white monitor screens. Further, if the obstacle detection processing is performed for each image signal, obstacles on the left and right roads can be detected.

[Brief description of the drawings]

FIG. 1 is a block diagram showing first and second embodiments of the present invention.

FIG. 2 is a diagram illustrating characteristics of a color filter and a wavelength selection filter of the color electronic camera.

FIG. 3 is a flowchart illustrating a calculation process according to the first embodiment of the present invention.

FIG. 4 is a flowchart illustrating a calculation process according to a second embodiment of the present invention.

FIG. 5 is a block diagram showing a third embodiment of the present invention.

[Explanation of symbols]

10, 11 ... Lens 20, 21 ... Wavelength selection filter 30 ... Lens case 40 ... Color electronic camera 41 ... Imaging surface 50, 51 ... Optical filter 60 ... Image processing unit 70 ... Mirror 80, 81 ... Monochrome monitor

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 7/18 H04N 7/18 V 9/04 9/04 BF Term (Reference) 5B047 AA19 AB04 BB04 BC05 BC07 CB23 5B057 AA06 AA16 BA02 CA01 CA08 CA12 CB02 CB08 CB13 CC01 CE16 DB03 DB05 DB09 5C022 AA04 AB68 AC42 AC54 AC55 AC69 5C054 AA01 EA01 HA30 5C065 AA07 DD01 EE02 EE03 EE12 EE20 GG30 GG44

Claims (5)

[Claims] 1. A first lens, a second lens, a first wavelength selection filter having a predetermined transmission wavelength band, and a second wavelength selection filter having a transmission wavelength band different from the first wavelength selection filter. A wavelength selection filter, and a color electronic camera having one imaging surface that captures an image formed through the first and second two lenses, wherein the light passing through the first lens is The color electronic camera is configured such that light reaching the imaging surface through one wavelength selection filter and passing through the second lens reaches the imaging surface through the second wavelength selection filter. By outputting two electric signals corresponding to the respective transmission wavelength bands of the two wavelength selection filters separately as image signals to be output from the image processing apparatus, the image processing unit for processing the two electric signals is provided. 1 and 2 screen simultaneous imaging processing apparatus characterized by simultaneously processing the second lens two screens inputted through. 2. The two-screen simultaneous imaging processing apparatus according to claim 1, wherein a first lens system including said first lens and a first wavelength selection filter, and said second lens and a second lens.
Both the second lens system composed of the wavelength selection filters of
A two-screen simultaneous imaging processing device, wherein two images having different luminances are simultaneously input and processed by adding an attenuation filter having a different attenuation rate or adding an attenuation filter only to one lens system. . 3. The two-screen simultaneous image processing apparatus according to claim 1, wherein the first wavelength selection filter has a transmission band of a wavelength that does not transmit an “R” filter of the color electronic camera. The second wavelength selection filter has a transmission band of a wavelength that does not pass through the “B” filter of the color electronic camera, and outputs “B” signal and “R” signal of a color signal as two output signals of the color electronic camera. And a two-screen simultaneous imaging processing device. 4. The two-screen simultaneous imaging processing apparatus according to claim 1, wherein a polarization filter is added to a first lens system including the first lens and a first wavelength selection filter, and wherein the second lens is provided. And an attenuation filter is added to a second lens system including a second wavelength selection filter to correct the relative positional shift between the two images output from the color electronic camera and to match the image density of the non-polarized portion of the subject. A two-screen simultaneous imaging processing apparatus, comprising: means for calculating a difference between the two images after performing density conversion to detect a polarization region on an imaging screen. 5. A two-screen simultaneous imaging processing apparatus according to claim 1, wherein a mirror is provided in front of said first and second lenses, and left and right sights having different angles are incident on each lens. By providing two black-and-white monitors that respectively display two image signals output from the color electronic camera as images, or by providing a unit that performs obstacle detection image processing on the two image signals, A two-screen simultaneous imaging processing device capable of detecting obstacles existing in both left and right directions.