JP2002335428A - Vehicle photographing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image photographing device acquiring an image including a driver and a vehicle identification plate that can more surely identify both the driver and the vehicle identification plate with a simpler device configuration. SOLUTION: In amplifying a photographed image including the driver 42 and the vehicle identification plate 44 at a prescribed amplification factor, the amplification factor for a 1st area S1 including the driver 42 is selected higher than the amplification factor for a 2nd area S2 including the vehicle identification plate 44. Since the image photographing device can acquire both images of the vehicle identification plate 44 and the driver 42 as clearer images, the identification performance of the both can be enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle photographing apparatus for photographing an image including a driver and a vehicle identification tag.
The present invention relates to a technique for more accurately identifying both a vehicle identification tag and a driver.

[0002]

2. Description of the Related Art When an image including a driver and a vehicle identification tag is taken, the brightness or the color of the image is different from each other. Can be difficult. That is, if the exposure condition is adjusted to the vehicle identification tag, the image of the driver is darkened. Conversely, if the exposure condition is adjusted to the driver, halation occurs in the image portion of the vehicle identification tag. As a countermeasure for this problem, for example, a technique disclosed in Japanese Patent Application Laid-Open No. H11-16100 is already known. In this technique, the lower side of the strobe light emitting portion is covered with a shielding plate to reduce the amount of light toward the vehicle identification slip, thereby enabling more reliable discrimination between the two.

[0003] In the above-mentioned prior art, it is sufficiently possible to discriminate both the vehicle identification slip and the driver, but it is meaningful if highly accurate discrimination can be realized with a simpler configuration.

[0004]

In a vehicle photographing apparatus according to the present invention, an image pickup section for acquiring an image including a driver and a vehicle identification tag, and an amplification section for amplifying the acquired image at a predetermined amplification factor. The amplification factor for the first region including the driver in the image acquired by the imaging unit is higher than the amplification factor for the second region including the vehicle identification tag. According to such a configuration, both the vehicle identification card and the driver can be more reliably identified with a simpler device configuration.

In the present invention, it is preferable that the amplification unit switches an amplification factor based on a control signal for outputting an acquired image from the imaging unit. This makes it possible to more reliably switch the amplification factor for the image information output from the imaging unit.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. First, a schematic configuration and operation of a vehicle photographing device 10 according to the present embodiment will be described with reference to FIG.

An image pickup unit 12 for obtaining a vehicle image including a vehicle identification tag and a driver of the vehicle is configured as an image pickup area of a solid-state image pickup device having, for example, a plurality of photoelectric conversion cells and a CCD shift register in an array. . The imaging unit 12 responds to the light reception amount (luminance value) of each photoelectric conversion cell based on a video output control signal (for example, a vertical synchronization signal VSYNC, a horizontal synchronization signal HSYNC, a clock pulse CP, and the like) from the control unit 16. The video signals (voltage signals) are sequentially output. This video signal corresponds to a captured image. The vehicle photographing apparatus 10 according to the present embodiment includes an optical system mechanism (a lens, a shutter, an aperture, and the like) (not shown).
The position and size of the acquired image, the amount of light received by the imaging unit 12, and the like are adjusted by controlling the optical system mechanism 6. Further, these optical system mechanisms may be controlled based on the detected vehicle speed.

[0008] The video signal for each photoelectric conversion cell output from the imaging unit 12 is sequentially amplified at a predetermined amplification rate in the amplification unit 14. The amplifying unit 14 can be configured as, for example, a video amplifier built in the solid-state imaging device and capable of variably setting an amplification factor. The amplification unit 14 switches the amplification factor based on the amplification control signal from the control unit 16 output in synchronization with the video output control signal.
With such a configuration, the amplification factor of the captured image can be set for each region, and the amplification processing can be performed in real time. The amplification control signal is transmitted to the DA converter 32
Is converted from a digital signal to an analog signal.

The control section 16 generates the amplification control signal based on the processing execution parameters. In the storage unit 20,
As this processing execution parameter, a region parameter indicating a region where the amplification factor is switched (for example, the number of the photoelectric conversion cell at which the switching of the amplification ratio starts or ends, the column [column] or the row [row] of the photoelectric conversion cell, or Timing and the like, and a gain parameter indicating the amplification factor (an absolute value of the gain or a relative value to a reference value, etc.) are stored in association with each other.

The processing execution parameters can be changed as appropriate based on the operation of the input unit 22 (for example, operation buttons and the like). That is, the processing parameter can be specified by operating the input unit 22, and any one of the plurality of registered parameters stored in advance in the storage unit 20 can be selected as the processing parameter. it can.
Further, it is possible to perform a shooting trial based on a preset trial parameter, display the shooting trial result on the display 24, and adopt a trial parameter with a good display result as a processing execution parameter. The trial parameter can be stored in the storage unit 20 as a registration parameter.

The processing execution parameters are selected from registered parameters. The registered parameters are stored in the storage unit 20 in association with the detected illuminance in the light detection unit 26 (for example, an illuminometer) that detects the brightness of the shooting environment. The processing execution parameter is selected from the registered parameters based on the detected illuminance. More specifically, for example, an illuminance range is set for each registered parameter, and the control unit 16 acquires a registered parameter having an illuminance range including the detected illuminance, and sets this as a processing execution parameter. As a result, a vehicle image corresponding to the brightness of the shooting environment can be obtained. Note that the imaging unit 12 can be used as the light detection unit 26. In this case, the total value or the average value of the luminance values of the video signals acquired from the imaging unit 12 can be used as the detected illuminance.

The vehicle photographing apparatus 10 is provided with a light emitting section 28 (for example, a strobe) for illuminating the photographed vehicle. Light emission (for example, light emission timing or light emission intensity) of the light emitting unit 28 is controlled by the control unit 16.

The video signal (photographed image) amplified by the amplifier 14 is converted into a digital signal by an AD converter 18 and then stored in an image memory area in a storage unit 20 (for example, a RAM or a hard disk device). Is done. The stored image is output from the printer 30 to a paper medium as needed.

The vehicle photographing apparatus 1 according to the present embodiment
0, the imaging unit 1 after the processing execution parameters are determined.
2 and the amplification process in the amplification unit 14 is performed, and the printout is performed. That is, the imaging unit 12
The process execution parameter cannot be changed between the time when the image is acquired by the printer 30 and the time when the image is output by the printer 30. Further, the vehicle photographing apparatus 10 cannot output photographed image data as an electronic medium. With the configuration described above, falsification of an image captured by the vehicle image capturing apparatus 10 is prevented.

Next, the amplification process in the amplification unit 14 will be described with reference to the drawings. FIG. 2 is an example of a photographing area S of the imaging unit 12. The imaging region S has 486 rows, and has 640 photoelectric conversion cells (hereinafter, referred to as pixels) for each row (however, the number of pixels in the uppermost row and the lowermost row is half). The video signal of each pixel is R1 to R243 from top to bottom every other row.
(Shown by a solid line in FIG. 2), and then R244 to R4
86 (indicated by broken lines in FIG. 2) are sequentially output (here, R ** is a row number). In each row, data is sequentially output from left to right. Note that, due to the optical system mechanism, the actual pixel arrangement and image in the imaging region S may be inverted in FIG. 2 both vertically and horizontally, but here, for the sake of explanation, the arrangement according to the actual image will be described. I do.

FIG. 3 is an explanatory diagram showing a photographed image on the photographing area S and an example of setting the first and second areas. The captured image includes a vehicle 40, a driver's (face) 42, and a vehicle identification slip 44. In the example of FIG.
The photographing area S is divided into upper, middle, and lower rows in units of rows, and the area of the image acquired by the upper rows (R1 to R90 and R244 to R333) is divided into a first area S1 and a lower row (R1).
51 to R243 and R394 to R486), the second region S2, the middle row (R91 to R486).
The region of the image acquired by R150 and R334 to R393) is defined as a transition region S3. In this example, the gain of the first area S1 is 1, the gain of the second area S2 is 0.5, and the gain of the transition area S3 is
The setting is made so as to change continuously from the first area to the second area.

Next, a change in the amplification factor in the amplifier 14 will be described with reference to FIGS. FIGS. 4 and 5 show an amplifying unit 1 for realizing the region setting example of FIG.
4 shows the change in the amplification factor at 4. 4 shows video signals (R1 to R1) input from the imaging unit 12 to the amplification unit 14.
243 and R244 to R468 are collectively described) and the vertical synchronizing signal input to the imaging unit 12,
The lower part shows a change in the amplification factor in the amplifier 14. Also, the upper part of FIG.
4 and the horizontal synchronizing signal input to the imaging unit 12, and the lower row shows the video signal (shown collectively for each row).
The change of the amplification factor in the amplifier 14 is shown. FIG. 5 is an enlarged view of the area A in FIG. 4, and the reference numerals (R88 to R92) in the video signal notation are row numbers. In each of these figures, the horizontal axis represents time.

As shown in FIG. 4, the vertical synchronizing signal (VSY)
NC) before the start of scanning in the vertical direction (that is, before starting output from R1 and before starting output from R244).
6 to the imaging unit 12, and the amplification unit 14 changes the amplification factor in synchronization with the vertical synchronization signal. For this purpose, the control unit 16 inputs the amplification control signal instructing the switching of the amplification factor to the amplification unit 14 in synchronization with the vertical synchronization signal. More specifically, in the example of FIG. 4, the control unit 16 determines the rising timing of the pulse of the vertical synchronization signal (time t).
= Ts1), an amplification control signal for instructing switching of the amplification factor from 0.5 to 1 is input to the amplification unit 14, and the amplification unit 14
Switches the amplification factor according to the amplification control signal.

As shown in FIG. 5, the horizontal synchronizing signal (H
SYNC) is input from the control unit 16 to the imaging unit 12 before the start of scanning in the horizontal direction (that is, before the start of output from each row [R1 to R486]). Change in synchronization with. For this purpose, the control unit 16 inputs the amplification control signal for instructing the switching of the amplification rate to the amplification unit 14 in synchronization with the horizontal synchronization signal. More specifically, in the example of FIG. 5, the control unit 16 determines the timing of the rising edge of the pulse of the horizontal synchronization signal (time t = t1).
, T121, t122, t123,...), An amplification control signal for instructing stepwise switching of the amplification rate (for example, decreasing the amplification rate by 0.008) is input to the amplification unit 14, and the amplification unit 14 Switches the amplification factor according to the amplification control signal. Note that time t = t13, t22, t23 in FIG.
At this timing, the amplification control signal is output from the control unit 16 in synchronization with the horizontal synchronization signal.

By the switching operation of the amplification rate synchronized with the vertical synchronizing signal and the horizontal synchronizing signal as described above, the first and second regions obtained by dividing the photographed image in units of rows can be amplified with different amplification rates. it can.

In the above example, a transition region whose amplification factor changes stepwise at the boundary between the first and second regions is provided. This makes it possible to improve the identifiability of a captured image (for example, a vehicle) other than the driver and the vehicle identification tag as compared with a case where the amplification factor is rapidly changed at the boundary between the first and second regions.

FIGS. 6 and 7 show other examples of setting the first and second areas. In this example, as shown in FIG. 6, the first and second areas are divided by both the row and the column of the imaging area S. Therefore, in this example, as shown in FIG. 7, the amplification factor is switched in synchronization with a clock pulse for sequentially outputting the video signal of each pixel from the imaging unit 12 to the amplification unit 14. The upper part of FIG.
The video signal (displayed for each pixel) input from the imaging unit 12 to the amplification unit 14 and the clock pulse signal input to the imaging unit 12 are shown, and the lower part shows a change in the amplification factor in the amplification unit 14.

The clock pulse signal is input from the control unit 16 to the imaging unit 12 at the timing of sequentially outputting the video signal of each pixel. More specifically, the control unit 16
The rising timing (time t = t31, t) of the pulse of the clock pulse signal for each pixel (R120, each of C147 to C150; C ** is a column number)
At 32, t33, and t34), an amplification control signal for instructing a stepwise change (for example, an increase) of the amplification factor is input to the amplification unit 14, and the amplification unit 14 switches the amplification factor by the amplification control signal. By switching the amplification rate in synchronization with the clock pulse signal in this manner, the first and second regions can be set to arbitrary positions or shapes.

[0024]

As described above, according to the present invention,
It is possible to more reliably identify both the vehicle identification slip and the driver with a simpler device configuration.

[Brief description of the drawings]

FIG. 1 is a block diagram of a vehicle photographing apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a configuration of a shooting area in an imaging unit of the vehicle shooting device according to the embodiment of the present invention.

FIG. 3 is a diagram illustrating an example of an image captured by a vehicle image capturing apparatus according to an embodiment of the present invention and first and second regions.

FIG. 4 is a diagram illustrating an example of switching of an amplification factor in synchronization with a vertical synchronization signal in the vehicle photographing apparatus according to the embodiment of the present invention.

FIG. 5 is a diagram illustrating an example of switching of an amplification factor in synchronization with a horizontal synchronization signal in the vehicle photographing apparatus according to the embodiment of the present invention.

FIG. 6 is a diagram illustrating another example of the image captured by the vehicle image capturing apparatus according to the embodiment of the present invention and the first and second regions.

FIG. 7 is a diagram illustrating an example of switching of an amplification factor in synchronization with a clock pulse in the vehicle photographing apparatus according to the embodiment of the present invention.

[Explanation of symbols]

10 vehicle photographing device, 12 imaging unit, 14 amplifying unit, 1
6 control unit, 18 AD conversion unit, 20 storage unit, 22
Input unit, 24 display, 26 light detection unit, 28
Light-emitting unit, 30 printer, 40 vehicle, 42 driver (face), 44 vehicle identification card.

Claims (2)

[Claims] An imaging unit that acquires an image including a driver and a vehicle identification tag; and an amplification unit that amplifies the acquired image at a predetermined amplification factor. A vehicle photographing apparatus, wherein an amplification factor for a first area including a driver is higher than an amplification factor for a second area including a vehicle identification tag. 2. The vehicle photographing apparatus according to claim 1, wherein the amplification unit switches an amplification factor in synchronization with a control signal for outputting the acquired image from the imaging unit. Vehicle photography device.